ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Organic Chemistry  (695)
  • Animals  (443)
  • AERODYNAMICS  (419)
  • 1980-1984  (1,557)
  • 1925-1929
  • 1982  (1,557)
  • 1
    Electronic Resource
    Electronic Resource
    Di- und Polyaminozucker, XXVIII1) Zur Substitution von 2-Amino-2-desoxy-α-D-glucopyranosiden in der 3-Stellung (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 265-274 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Di- and Polyamino Sugars, XXVIII1). - Substitution Reactions of 2-Amino-2-deoxy-α-D-gluco-pyranosides at Position 3Nucleophilic substitutions of N-protected 2-amino-2-deoxy-3-O-mesyl-α-D-glucopyranosides with azide ions were severely restricted by neighboring group participations. N-acetyl as blocking group (2) led to the formation of the oxazoline 3 while from N-dinitrophenyl derivatives (9; 17) isomeric products (10, 11; 18, 19) were formed via epimines. Structure proofs were given by spectroscopy as well as by independent syntheses.
    Notes: Nucleophile Substitutionen an N-geschützten 2-Amino-2-desoxy-3-O-mesyl-α-D-glucopyranosiden mit Azid-Ionen wurden durch Nachbargruppenreaktionen behindert. N-Acetyl als Schutz-gruppe (2) führte zum Oxazolin 3, aus Dinitrophenyl-Derivaten (9; 17) wurden über Epimine isomere Produkte (10, 11; 18, 19) erhalten. Die Konstitutionsbeweise wurden sowohl anhand der Spektren als auch durch unabhängige Synthesen geführt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Sulfosilylierung von Aromaten mit Chlorsulfonsäure-trimethylsilylester (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 282-297 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sulfosilylation of Aromatic Hydrocarbons by Trimethylsilyl ChlorosulfonateAromatic hydrocarbons 2, 6, 8, 9, 13, 16, 18, 19, 22 react with trimethylsilyl chlorosulfonate (1) to give trimethylsilyl arenesulfonates 5, 7, 11, 12, 15, 23 or sulfonic acids 17, 20, 21. If trimethylsilyl sulfonates are obtained, working up of the sulfonation mixtures is possible by distillation. By hydrohalogenolysis of trimethylsilyl sulfonates 5 at 0-5°C anhydrous sulfonic acids 3 result. The pathways to diphenylsulfone (25a) in the reaction of benzene (2a) with 1 were investigated. In this connection we succeeded in synthesizing benzenepyrosulfonic acid (28) and trimethylsilyl benzenepyrosulfonate (29).
    Notes: Durch Umsetzung der Aromaten 2, 6, 8, 9, 13, 16, 18, 19, 22 mit Chlorsulfonsäure-trimethylsilylester (1) erhält man die Arensulfonsäure-trimethylsilylester 5, 7, 11, 12, 15, 23 bzw. Sulfonsäuren 17, 20, 21. Die Aufarbeitung der Sulfonierungsgemische erfolgt, wenn Silylester entstehen, destillativ. Aus der Hydrohalogenolyse der Trimethylsilylester 5 bei 0-5°C resultieren die wasserfreien Sulfonsäuren 3. Am Beispiel der Reaktion von Benzol (2a) mit 1 werden die Möglichkeiten der Bildung von Diphenylsulfon (25a) untersucht. In diesem Zusammenhang gelang die Synthese von Benzolpyrosulfonsäure (28) und Benzolpyrosulfonsäure-trimethylsilylester (29).
    Additional Material: 11 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Zur Struktur eines neuen Nortriterpens aus den Bulbi von Scilla scilloides Druce1) (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 306-314 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of a New Nortriterpene from the Bulbs of Scilla scilloides Druce1)From the acetone extract of the bulbs of Scilla scilloides Druce (Liliaceae) the new nortriterpene 1 has been isolated. The structure of 1 was established on the basis of chemical and spectral evidences. Besides the free state 1 was obtained by mild acid hydrolysis of the acetone-insoluble and methanol-soluble fraction suggesting the existence of 1 also in the form of its glycosides.
    Notes: Aus dem Acetonextrakt der Bulbi von Scilla scilloides Druce (Liliaceae) wurde das neue Nortriterpen 1 isoliert. Auf Grund der chemischen und spektroskopischen Untersuchungen ließ sich die Struktur von 1 ermitteln. Neben dem frei enthaltenen 1 wurde offenbar glycosidisch gebundenes 1 bei der milden Säurehydrolyse der in Aceton unlöslichen und in Methanol löslichen Fraktion erhalten.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Regioselektive Synthese der N-Monomethyl-Derivate des 7-Desazahypoxanthins (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 805-812 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Regioselective Synthesis of the N-Monomethyl Derivatives of 7-DeazahypoxanthineMethylation of 3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one (1a) or its 2-methylthio derivative with dimethyl sulfate in alkaline solution leads preferentially to the 3-methyl derivatives 2a or 2b, respectively. The N-1 isomer 3, however, is obtained by condensation of ethyl 2-cyano-4,4-diethoxybutyrate with N-(methyl)thiourea via the pyrimidine 4a which after cyclisation to 5a was desulfurised to 3. Phase-transfer methylation of 4-methoxy-2-methylthio-7H-pyrrolo[2,3-d] pyrimidine furnishes 8a which after ether cleavage and desulfurisation gave the N-7-methyl isomer 8c.
    Notes: Die Methylierung von 3,7-Dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-on (1a) oder seines 2-Methylthioderivates mit Dimethylsulfat führt im alkalischen Medium bevorzugt zu den N-3-Methyl-Derivaten 2a bzw. 2b. Das N-Isomer 3 wird hingegen durch Kondensation von 2-Cyan-4,4-diethoxybuttersäure-ethylester mit N-(Methyl)thioharnstoff über das Pyrimidinderivat 4a durch Cyclisierung zu 5a und anschließende Desulfurierung erhalten. Phasentransfer-Methylierung von 4-Methoxy-2-methylthio-7H-pyrrolo[2,3-d]pyrimidin führt zu 8a, aus dem durch Etherspaltung und Entschwefelung das N-7-Methylisomer 8c entsteht.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820421
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A Short Synthesis of Muscimol (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 817-820 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eine kurze Synthese von MuscimolMuscimol (1) wurde, ausgehend von Acetylendicarbonsäure-dimethylester (3) und N-Hydroxyharnstoff, in 3 Schritten mit 30proz. Ausbeute synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820423
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Zur Addition von CH-aciden Verbindungen an die CC-Dreifachbindung (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 989-993 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A Contribution to the Addition of CH-acidic Compounds to the CC Triple BondIn an addition-isomerisation reaction α-alkyl- and α-arylbenzylcyanides 1 add phase-transfer catalysed to 1-propargylazoles 2 yielding substituted 4-azolyl-3-methyl-3-butenenitriles 3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Massenspektrometrische Untersuchung langkettiger Alkatriene Nachweis eines strukturspezifischen Dienfragmentes (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1001-1005 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass Spectrometric Analysis of Long-chain Alkatrienes  -  Evidence of a Structure Specific Diene FragmentEI mass spectra of 1,n,(n + 2)-alkatrienes show structure specific fragments which allow the determination of the double bond position.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820521
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Masthead (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Stoffwechselprodukte von Mikroorganismen, 2041) Die Struktur von Imacidin C (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 28-40 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolic Products of Microorganisms, 2041) - The Structure of Imacidin CImacidin C, the main peptide antibiotic from Streptomyces olivaceus, has been identified as (R)-β-hydroxyisotridecanoic decapeptide lactone 5. This paper describes the analysis of its lactone linkage and amino acid sequence by chemical degradation and partial hydrolysis. The amino acid configuration was determinated enzymatically and by gas chromatography on chiral phase.
    Notes: Imacidin C, der Hauptbestandteil einer Gruppe chemisch ähnlicher Peptidantibiotica aus Streptomyces olivaceus, wurde als (R)-β-Hydroxyisotridecanoyl-decapeptidlacton 5 identifiziert. Aminosäuresequenz und Größe des Lactonringes wurden durch Partialhydrolyse und Abbaureaktionen ermittelt, die Konfiguration der Aminosäuren enzymatisch und durch Gaschromatographie an chiraler Phase bestimmt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Lichtinduzierte Reaktionen an Morphinderivaten, 31) Photo-Beckmann-Umlagerung 2. Art (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 112-117 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced Reactions of Morphine Derivatives, 31) - 2nd Order Photo Beckmann RearrangementIrradiation of the oxime 1b leads to a fragmentation reaction, called second-order photo Beckmann rearrangement. A C-C bond is splitted with formation of a triple CN bond and a methoxy, ethoxy, or hydroxy group is introduced. On heating with acid, the nitriles 3a, b and 7a are transformed into the lactam 6.
    Notes: Die Bestrahlung des Oxims 1b führt zu einer als Beckmann-Reaktion 2. Art bezeichneten Fragmentierungsreaktion. Unter C-C-Bindungsspaltung kommt es zur Ausbildung einer CN-Dreifachbindung und zur Einführung einer Methoxy-, Ethoxy- oder Hydroxy-Gruppe. Beim Erhitzen mit Säure werden die Nitrile 3a, b und 7a in das Lactam 6 umgewandelt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Ein neuartiges dimeres Corrinoid mit Bisallyl-Struktur (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 118-120 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Dimeric Corrinoid with Bisallyl StructureOn thermolysis of heptamethyl dicyanocobyrinate (in decalin at 190°C), a dimer is formed (among other products) which according to its 13C and 1H-NMR data and its molecular mass possesses the structure of tetracyanobis(7-decarboxymethyl-7,8-didehydro-5-methylene-5-norcobyrinic acid) dodecamethyl ester (2).
    Notes: Bei der Thermolyse von Dicyanocobyrinsäure-heptamethylester (in Decalin bei 190°C) bildet sich u. a. ein Dimeres, dessen Konstitution sich aufgrund von 13C- und 1H-NMR-Daten sowie der Molmasse als Tetracyanobis(7-decarboxymethyl-7,8-didehydro-5-methylen-5-norcobyrinsäure)-dodecamethylester (2) ergibt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Synthese von cis- und trans-Eninen in der Reihe der 12-und 15-Ringe (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1366-1374 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of cis- and trans-Enynes in the Class of 12- and 15-membered Ring SystemsSynthesis of (E)-1-cyclododecen-3-yne (E-2a) leads to the isolation of the first trans-enyne with geometrical ring strain. E-2a isomerizes thermally to give the Z-configuration Z-2a in a very smooth reaction. For systematical investigations the 15-membered ring enynes E-5a and Z-5a were generated. They behave like openchained 1,3-enynes.
    Notes: Die Synthese von (E)-1-Cyclododecen-3-in (E-2a) führt zur Isolierung des ersten trans-Enins mit geometrischer Ringspannung. E-2a wandelt sich thermisch leicht in die Z-Konfiguration Z-2a um. Zur systematischen Untersuchung werden die 15-Ring-Enine E-5a und Z-5a hergestellt. Sie verhalten sich wie offenkettige 1,3-Enine.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820713
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Synthesen mit aliphatischen Dialdehyden, XXXIV. Versuche zur Darstellung von Brom-(Chlor-)fluormalonaldehyd sowie von Fluor(methyl)- und Fluor(phenyl)malonaldehyd (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1348-1358 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Aliphatic Dialdehydes, XXXIV.  -  Attempts to Synthesize Bromo- or Chloro-fluoromalonaldehyde and Fluoro(methyl)- or Fluoro(phenyl)malonaldehydeFluorination of the potassium salts of chloro- (3), methyl- (10), and phenylmalonaldehyde (12) with perchloryl fluoride in methanol at 27-28°C leads to the 2-substituted fluoromalonaldehyde bis(methyl semiacetals) 4 and 13a, b, respectively, which in turn can be converted into the more stable derivatives 5, 7-9 of chlorofluoromalonaldehyde (2a), and 14a, b of fluoro(methyl)- and fluoro(phenyl)malonaldehyde, respectively. The corresponding free 2,2-disubstituted malon-aldehydes mentioned in the title were not available due to their tendency to polymerize. Attempts to obtain fluoro(methyl)malonaldehyde from its bis(dimethyl acetal) 14a gave only a “dimer”, the 9,10-difluoro-9,10-dimethyl-2,4,6,8-tetraoxaadamantane (15). The derivatives 5, 7-9 as well as 14a, b of the 2,2-disubstituted malonaldehydes are useful bifunctional C3-synthons.
    Notes: Fluorierung der Kaliumsalze von Chlor- (3), Methyl- (10) und Phenylmalonaldehyd (12) mit Perchlorylfluorid in Methanol bei 27-28°C führt zu den 2-substituierten Fluormalonaldehyd-bis(methylhalbacetalen) 4 bzw. 13a, b, die in die stabileren Derivate 5, 7-9 des Chlorfluor-malonaldehyds (2a) bzw. 14a, b von Fluor(methyl)- und Fluor(phenyl)malonaldehyd übergeführt werden können. Die entsprechenden freien, im Titel genannten Malonaldehyde konnten wegen ihrer Neigung zur Polymerisation nicht erhalten werden. Versuche, den Fluor(methyl)malon-aldehyd aus seinem Bis(dimethylacetal) 14a zu gewinnen, führten zu einem “Dimeren”, dem 9,10-Difluor-9,10-dimethyl-2,4,6,8-tetraoxaadamantan (15). Die Derivate 5, 7-9 sowie 14a, b der 2,2-disubstituierten Malonaldehyde sind nützliche bifunktionelle C3-Synthesebausteine.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820711
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Über die Veresterung von Glycerinaldehyd-diethylacetal mit einigen Aminosäuren (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 366-371 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Esterification of Glyceraldehyde Diethyl Acetal with Some Amino AcidsGlyceraldehyde diethylacetal was selectively esterified in the 2- and 3-position, respectively, by several Z-amino acids. Attempts to remove the protective groups usually result in hydrogenolytic or hydrolytic cleavage of the ester bond.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820220
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Synthese cyclischer N-(2-Arylvinyl)harnstoffe durch Wittig-Reaktion (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 372-375 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Cyclic N-(2-Arylvinyl)ureas by Wittig ReactionTriphenyl(α-ureidoalkyl)phosphonium salts (1, 2, 8) react with aromatic aldehydes and ketones to give quite easily N-(2-arylvinyl)ureas (4a, b, 5a-i, 7, 9) according to Wittig.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820221
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Indole und Indolalkaloide, XVIII. Synthese von Tetrahydro- und Hexahydrocarbazol-Derivaten mit N-Substituenten in Position 4 (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 739-744 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Indoles und Indole Alkaloids, XVIII1).  -  Synthesis of Tetrahydro- and Hexahydrocarbazoles with N-Substituents in Position 4Synthesis and properties of some tetrahydro- and hexahydrocarbazoles bearing N-substituents in position 4 are described Tricyclic representatives of this type have been unknown up to this time.
    Notes: Es werden Darstellung und Eigenschaften einiger Tetrahydro- und Hexahydrocarbazol-Derivate mit N-Substituenten in Position 4 beschrieben. Tricyclische Vertreter dieses Typs waren bisher noch nicht bekannt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820415
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    A Ready Conversion of a Pregnane-20-carboxaldehyde to 17α-Hydroxypregnan-20-ones and Pregn-16-en-20-ones (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1829-1835 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Einfache Umwandlung eines Pregnan-20-carboxaldehyds in 17α-Hydroxypregnan-20-one und Pregn-16-en-20-oneUmsetzung von (20S)-5α-Chlor-3β-hydroxypregnan-20-carboxaldehyd (9, dargestellt in zwei Stufen aus Stigmasterin) mit Sauerstoff und Kalium-tert-butylat sowie anschließend mit Trimethylphosphit lieferte 5α-Chlor-3β,17α-dihydroxypregnan-20-on (6) und 3β, 17α-Dihydroxypregn-5-en-20-on (7). Diese Mischung wurde durch Kaliumhydroxid in 7 übergeführt, während Reaktion mit Pyridinium-dichromat und danach mit Kaliumhydroxid 17α-Hydroxypregn-4-en-3,20-dion (8) ergab. Bromierung-Dehydrobromierung von 9 in einer oder zwei Stufen ergab (Z)- und (E)-5α-Chlor-3β-hydroxypregn-17(20)-en-20-carboxaldehyd (11). Dessen Reaktion mit Sauerstoff und Kaliumhydroxid lieferte 5α-Chlor-3β-hydroxypregn-16-en-20-on (12). Letzteres wurde durch weitere Kaliumhydroxid-Behandlung in 3β-Hydroxypregna-5,16 dien-20-on (13) und mittels Oppenauer-Reaktion, unter Anwendung von überschüssigem Aluminiumisopropylat, in Pregna-4,16-dien-3,20-dion (14) übergeführt.
    Notes: Reaction of (20S)-5α-chloro-3β-hydroxypregnane-20-carboxaldehyde (9, prepared in two steps from stigmasterol) with oxygen and potassium tert-butoxide, followed by trimethyl phosphite treatment, afforded 5α-chloro-3β,17α-dihydroxypregnan-20-one (6) and 3β,17α-dihydroxypregn-5-en-20-one (7). This mixture was converted into 7 by potassium hydroxide treatment, and into 17α-hydroxypregn-4-ene-3,20-dione (8) by reaction with pyridinium dichromate followed by potassium hydroxide treatment. Bromination-dehydrobromination of 9, in one or two steps, afforded (Z)- and (E)-5α-chloro-3β-hydroxypregn-17(20)-ene-20-carboxaldehyde (11). Reaction of 11 with oxygen and potassium hydroxide gave 5α-chloro-3β-hydroxypregn-16-en-20-one (12), which was converted to 3β-hydroxypregna-15,6-dien-20-one (13) by further potassium hydroxide treatment, and to pregna-4,16-diene-3,20-dione (14) by Oppenauer reaction using excess aluminium isopropoxide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821007
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Glycosylazide als Ausgangsbasis zur Gewinnung von Nucleosidanalogen, 2. Synthese von Tetrazol-Nucleosiden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1870-1890 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Glycosyl Azides as Starting Materials for the Synthesis of Nucleoside Analogues, 2.  -  Synthesis of Tetrazole NucleosidesThe β-D-ribofuranosyl azide derivative 1 as well as the corresponding α-anomeric compound 3 yield via Staudinger reaction the same P-N-ylide 2. Treatment with alkyl isocyanates RNCO [R = CH3, (CH3)2CH, C2H5OCOCH2, (S)-C2H5OCOCH(CH3)] affords the diastereomeric carbodiimide derivatives 5 which can be transformed by HN3 regioselectively into the 1-(β-ribofuranosyl)-5-(alkylamino)tetrazole derivatives 6. Partial or total removal of the protecting groups affords the products 7a, c, d, and 7d′-d′". The β-D-mannofuranosyl azide derivative 8 is converted via the P-N-ylide 9 into the carbodiimide 10 and the aminotetrazole derivative 11. The reaction of 2 with phenyl isocyanate yields the 5-[(β- and 5-[(α-D-ribofuranosyl)amino]-1-phenyltetrazoles 18 and 19 passing the carbodiimide intermediates 12 and 13. Additionally the 1-isocyanato sugar derivatives 14 and 15 arise which provide for the formation of the products 16, 17, and 20-22. The ethyl [(β-D-ribofuranosyl)-5-tetrazolyl]acetate 23 is formed by reaction of 2 with the azide of monoethyl malonate. The preparation of the ribosyltetrazole derivatives 26 and 27 can be achieved only by preceding synthesis of the syn/anti mixture 24a/24a originating from 2 and acetyl cyanide followed by treatment with HN3. The α-ribosyliminonitrile 25 is assumed to be an intermediate.
    Notes: Sowohl das β-D-Ribofuranosylazid 1 als auch das α-Anomere 3 liefern bei der Staudinger-Reaktion das gleiche P-N-Ylid 2. Mit Alkylisocyanaten RNCO [R - CH3, (CH3)2CH, C2H5OCOCH2 und (S)-C2H5OCOCH(CH3)] entstehen die Carbodiimidderivate als Diastereomerengemische 5, welche mit HN3 in die 1-(β-Ribofuranosyl)-5-(alkylamino)tetrazole 6 umgewandelt werden. Teilweise oder gänzliche Entfernung der Schutzgruppen führt zu den Produkten 7a, c, d und 7d′-d′". Vom β-D-Mannofuranosylazidderivat 8 aus gelangt man über das P-N-Ylid 9 zum Carbodiimidderivat 10 und schließlich zum Aminotetrazolderivat 11. Die Umsetzung von 2 mit Phenylisocyanat liefert die 5-[(β- und 5-[(α-D-Ribofuranosyl)amino]-1-phenyltetrazole 18 bzw. 19 über die Carbodiimidzwischenstufen 12 und 13. Ferner entstehen die 1-Isocyanatozuckerderivate 14 und 15, welche für die Entstehung der Folgeprodukte 16, 17 und 20-22 verantwortlich sind. Aus 2 und Malonsäure-monoethylester-azid entsteht das Nucleosidderivat 23. Die Darstellung der Ribosyltetrazole 26 und 27 aus 2 läßt sich nur mit Acetylcyanid über das syn/anti-Gemisch 24a/24a′ durch Umsetzung mit HN3 verwirklichen. Als Zwischenstufe wird das (α-Ribosylimino)nitril 25 postuliert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Masthead (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820601
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Synthese neuer 4,4-Diaryl-2-chlor-2-buten-4-olide und einfacher Zugang zu 1,1-Diphenylinden-3-carbonsäure (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1017-1021 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of New 4,4-Diaryl-2-chloro-2-buten-4-olides and a Simple Route to 1,1-Diphenylindene-3-carboxylic AcidOn heating in dimethylformamide, 4,4-diaryl-2,3-dichloro-2-butenoic acids 2 cyclize to give new 4,4-diaryl-2-chloro-2-buten-4-olides 3. Reaction of 1,2,4-triazole or pyrazole with 3 yields 4,4-diaryl-3-azolyl-2-buten-4-olides 5.  -  Friedel-Crafts reaction of 3a with benzene yields 1,1-diphenylindene-3-carboxylic acid (7).
    Notes: 4,4-Diaryl-2,3-dichlor-2-butensäuren 2 cyclisieren beim Erwärmen in Dimethylformamid zu neuen 4,4-Diaryl-2-chlor-2-buten-4-oliden 3. Mit 1,2,4-Triazol oder Pyrazol reagiert 3 zu 4,4-Diaryl-3-azolyl-2-buten-4-oliden 5.  -  Friedel-Crafts-Reaktion von 3a mit Benzol führt zu 1,1-Diphenyl-inden-3-carbonsäure (7).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Regio- und Stereoselektivität der Lactonbildung bei der Hydrolyse der PO-Olefinierungsprodukte von α,β-Epoxycyclohexanonen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1150-1157 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Regio- and Stereoselectivity of the Lactone Formation via Hydrolysis of the PO-Olefination Products of α,β-EpoxycyclohexanonesPO-Olefination of the diastereomeric pulegone oxides 1 and 2 with 9a leads to (E,Z) esters, 1 affording mainly (E)-3, and 2 predominantly (Z)-4. (Z)-4 hydrolyzes to give a mixture of γ- and δ-lactones 6-8; whereas (Z)-3 yields stereoselectively the δ-lactone 5.  -  The epoxy ketone 12 reacts with 9b to give the (E,Z) ester 13. (Z)-13 stereoselectively yields the γ-lactone 14.
    Notes: Bei der PO-Olefinierung der diastereomeren Pulegonepoxide 1 und 2 mit 9a erhält man (E,Z)-Säureester, und zwar aus 1 überwiegend (E)-3, aus 2 vorwiegend (Z)-4. (Z)-4 hydrolysiert zum γ- und δ-Lactongemisch 6-8; (Z)-3 hingegen liefert stereoselektiv das δ-Lacton 5.  -  Das Epoxyketon 12 reagiert mit 9b zum (E,Z)-Säureester 13. (Z)-13 ergibt stereoselektiv das γ-Lacton 14.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820616
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Präparative Aspekte der aus β-Dicarbonylverbindungen synthetisierbaren 1,3-Dithiolane (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1158-1172 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparative Aspects of 1,3-Dithiolanes Synthesizable from β-Dicarbonyl CompoundsThe reaction of 1,2-ethanedithiol (1) with the β-dicarbonyl compounds 2 leads to the 1,3-dithiolanes 3 which are accessible to regioselective reactions at the free carbonyl function. Thus the derivatives of the β-keto acid esters can be hydrolyzed to give the corresponding carboxylic acids 4 which make the ester group modified 1,3-dithiolanes 3 accessible in good yields. Addition of trimethyloxonium tetrafluoroborate produces the monodithiolanium salts 6 which on hydrolysis rapidly decompose into 2 and the vinyl thioethers 8. Reaction of 3 with the Grignard reagents 10 yields the 2-(2-hydroxyalkyl)-1,3-dithiolanes 11. Dethioacetalization of 11 with HgO/BF3 leads to the β-hydroxy ketones 12. The retro reaction of 3 leads to the basic compounds 2 which, however, are obtained only in moderate yields.  -  Finally the performance of the sensitive silylenol ether 13 starting from 3g is described.
    Notes: Aus 1,2-Ethandithiol (1) und den β-Dicarbonylverbindungen 2 werden die 1,3-Dithiolane 3 erhalten, die regioselektiven Reaktionen an der noch freien Carbonylfunktion zugänglich sind. So lassen sich die Derivate der β-Ketocarbonsäureester zu den Carbonsäuren 4 hydrolysieren, die bei der Veresterung mit den Alkanolen 5 die estergruppenmodifizierten 1,3-Dithiolane 3 liefern. Einwirkung von Trimethyloxonium-tetrafluoroborat ergibt die Monodithiolaniumsalze 6, die bei der Hydrolyse rasch in 2 und die Vinylthioether 8 zerfallen. Umsetzung von 3 mit den Grignardreagenzien 10 ergibt die 2-(2-Hydroxyalkyl)-1,3-dithiolane 11. Dethioacetalisierung von 11 mit HgO/BF3 führt zu den β-Hydroxyketonen 12. Die Rückspaltung von 3 zu 2 gelingt nur in mäßigen Ausbeuten.  -  Schließlich wird noch die Darstellung des empfindlichen Silylenolethers 13 aus 3g beschrieben.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820617
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Synthese und Reaktionen der 3-O-Phosphoniogluco-und -allofuranosen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1245-1260 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of 3-O-Phosphoniogluco- and AllofuranosesStarting from the bicyclic gluco- (3, 5, 7, and 9) and allofuranoses 11 the isolable 3-O-phosphonio-carbohydrates (4, 6, 8, 10, and 12) were synthesized by reaction with triphenylphosphane (1), diethyl azodicarboxylate (2), and alkylating or acylating agents. On heating, the various allo configurated salts 12 are converted into the corresponding at C-3 epimeric gluco configurated substitution products offering a wide range of flexibility. The reactions of the gluco configurated salts depend strongly on the type of nucleophile to be introduced and from neighboring groups in the carbohydrate skeleton. The iodide 4a and the azide 4g react by substitution forming the allo derivatives 15. In contrast, bromide, chloride, and sulfonate as gegen-ions mainly cause rearrangement of the 5,6-isopropylidene bridge or opening of the 5,6-anhydro structure.
    Notes: Aus den bicyclischen Gluco- (3, 5, 7 und 9) und Allofuranosen 11 werden mit Triphenylphosphan (1), Azodicarbonsäure-diethylester (2) und Alkylierungs- oder Acylierungsmitteln isolierbare 3-O-Phosphoniokohlenhydrate (4, 6, 8, 10 und 12) hergestellt. Durch Erwärmen der allo-konfigurierten Salze 12 können an C-3 epimere gluco-konfigurierte Substitutionsprodukte in großer Vielfalt gewonnen werden. Die Reaktionen der gluco-konfigurierten Salze werden stark vom Charakter des einzuführenden Nucleophils und von Nachbargruppen im Kohlenhydratgerüst beeinflußt. Während das Iodid 4a und das Azid 4g unter Substitution zum allo-Derivat 15 reagieren, tritt in den Fällen mit Bromid, Chlorid oder Sulfonat als Gegen-Ion Umlagerung von 5,6-Iso-propylidenbrücken bzw. öffnung von 5,6-Anhydrostrukturen ein.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820703
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Tetrapyrrol-Biosynthese, 14. Extrem selektive Porphyrin-Bildung bei der Cyclisierung verschiedener Oligopyrrole (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1272-1279 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetrapyrrole Biosynthesis, 141).  -  Extremely Selective Porphyrin Formation by Cyclization of Different OligopyrrolesIn order to gain insight into the formation tendency of porphyrins, the acid catalysed condensation of the linear oligopyrroles 12-d, 18, and 19 was investigated in several combinations. Although the formation of cyclic tetra-, penta-, hexa-, and heptapyrroles might in principle be possible herewith, only cyclization to the porphyrin 13 under elimination of monopyrrole units took place in every case. This remarkable behaviour of the oligopyrroles is caused by their favoured helical conformation, which always forces their cyclization to the porphyrin system.
    Notes: Um Einblick in die Bildungstendenz der Porphyrine zu gewinnen, wurde die säurekatalysierte Kondensation linearer Oligopyrrole 12a-d, 18 und 19 in verschiedenen Kombinationen untersucht. Obwohl hierbei im Prinzip die Bildung cyclischer Tetra-, Penta-, Hexa- und Heptapyrrole möglich wäre, erfolgte in jedem Falle Cyclisierung zum Porphyrin 13 unter Eliminierung von Monopyrrol-Einheiten. Ursache für dieses bemerkenswerte Verhalten der Oligopyrrole ist deren begünstigte helikale Konformation, die stets den Ringschluß zum Porphyrin-Grundgerüst erzwingt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820705
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Conformation of peptides containing α-Aminoisobutyric acid the crystal structure of Boc-Gly-l-Ala-Aib-OMe (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1322-1329 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Konformation von Peptiden mit α-Aminoisobuttersäure.  -  Die Kristallstruktur von Boc-Gly-L-Ala-Aib-OMeBoc-Gly-L-Ala-Aib-OMe (1) kristallisiert in der Raumgruppe P212121 mit a = 10.043(3), b = 11.590(5), c = 16.779(1) Å und Z = 4 (R-Faktor für 1859 symmetrieunabhängige Reflexe: 0.043). Das Tripeptid bildet über eine 4 → 1-intramolekulare Wasserstoffbrückenbindung einen “β-turn”-Typ III, obwohl das Cα-Atom im Aib-Rest nicht direkt an dem “β-turn”-Ringsystem beteiligt ist. Intermolekulare Wasserstoffbrücken verknüpfen die Einzelmoleküle schraubenförmig entlang [100].
    Notes: Boc-Gly-L-Ala-Aib-OMe (1) crystallizes in the space group P212121 with a = 10.043(3), b = 11.590(5), c = 16.779(1) Å, and Z = 4 (R value for 1859 symmetry independent reflexions: 0.043). On the basis of a 4 → 1 intramolecular hydrogen bond, the tripeptide forms a β-turn type III, although the Cα atom in the Aib residue is not directly involved in the β-turn ring system. Inter-molecular hydrogen bonds link the single molecules to helical structures along [100].
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820709
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Reaktionen von Kohlenhydrat-Acetalen mit Organolithiumverbindungen. Synthese einer 3-Desoxy-α-D-erthro-hexofuranosid-2-ulose und 6-Desoxy-α-D-xylo-hexofuranos-5-ulose (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1543-1547 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Carbohydrate Acetals with Organolithium Compounds.  -  Synthesis of 3-Deoxy-α-D-erythro-hexofuranosid-2-ulose and 6-Deoxy-α-D-xylo-hexofuranos-5-uloseMethyl 2,3:5,6-di-O-isopropylidene-α-D-mannofuranoside (1) reacts with lithium diisopropylamide to give the methyl 3-deoxy-5,6-O-isopropylidene-α-D-erythro-hexofuranosid-2-ulose (2), while 1,2-O-isopropylidene-3,5,6-O-methylidyne-α-D-glucofuranose (3) yields 6-deoxy-1,2-O-isopropylidene-α-D-xylo-hexofuranos-5-ulose (4).
    Notes: Das Methyl-2,3:5,6-di-O-isopropyliden-α-D-mannofuranosid (1) reagiert mit Lithiumdiisopropylamid zur Methyl-3-desoxy-5,6-O-isopropyliden-α-D-erythro-hexofuranosid-2-ulose (2), während die 1,2-O-Isopropyliden-3,5,6-O-methylidin-α-D-glucofuranose (3) die 6-Desoxy-1,2-O-isopropyliden-α-D-xylo-hexofuranos-5-ulose (4) liefert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820813
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Synthesen mit α-metallierten Isocyaniden, LI. Diastereoselektive Synthese von Ethyl-(2S,3S,4R)- und -(2R,3R,4R)-2-amino-3,4,5-trihydroxypentanoat (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1548-1552 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with α-Metalated Isocyanides, LI.  -  Diastereoselective Synthesis of Ethyl (2S,3S,4R)- and (2R,3R,4R)-2-Amino-3,4,5-trihydroxypentanoateEthyl isocyanoacetate (1) reacts (base-induced) with 2,3-O-isopropylidene-D-glyceraldehyde (3) to give the two diastereomeric 5-(4-dioxolanyl)-2-oxazoline-4-carboxylic acid esters 4 and 5 with trans configuration at the oxazoline ring. Acid hydrolysis of 4 or 5 gives the title compounds 6a and 7a which were characterized as their tetraacetates 6b and 7b.  -  Analogously, 2,3-O-isopropylidene-D-erythrose (10) gives with 1 the two diastereomeric trans-2-oxazoline-4-carboxylic acid esters 11 and 12.
    Notes: Isocyanessigsäure-ethylester (1) reagiert (baseninduziert) mit 2,3-O-Isopropyliden-D-glycerin-aldehyd (3) zu den beiden 5-(4-Dioxolanyl)-2-oxazolin-4-carbonsäure-ethylestern 4 und 5 mit trans-Konfiguration am Oxazolinring, d. h. die Konfiguration an C-4 paßt sich jeweils der an C-5 an. Saure Hydrolyse von 4 oder 5 liefert die Titelverbindungen 6a und 7a, die als Tetraacetate 6b und 7b charakterisiert wurden.  -  2,3-O-Isopropyliden-D-erythrose (10) reagiert analog mit 1 zu den beiden diastereomeren trans-2-Oxazolin-4-carbonestern 11 und 12.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820814
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Synthese der N-terminalen Aminosäure der Nikkomycine I, J, X und Z (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1615-1622 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the N-Terminal Amino Acid of the Nikkomycins I, J, X, and ZA mixture of four stereoisomers of 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutanoic acid (14), the N-terminal amino acid of the nikkomycin antibiotics could be synthesized in a twelve-step procedure. By comparison of 1H NMR spectra, mass spectra and of the gas chromato-graphic behaviour of various derivatives the constitution and relative configuration of the natural compound has been confirmed.
    Notes: Ein Gemisch aus vier Stereoisomeren von 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbuttersäure (14) der N-terminalen Aminosäure der Nikkomycin-Antibiotika konnte in einer zwölfstufigen Synthese dargestellt werden. Durch Vergleich der 1H-NMR-Spektren, Massenspektren und des gaschromatographischen Verhaltens verschiedener Derivate von Synthese- und Naturprodukt wird die Richtigkeit der angenommenen Konstitution und relativen Konfiguration bestätigt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Neue 4-Chinolinol- und 5,6,7,8-Tetrahydro-4-chinolinol-abkömmlinge mit biozider Wirkung (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1656-1676 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New 4-Quinolinol- and 5,6,7,8-Tetrahydro-4-quinolinol Derivatives with Biocidal EffectThe synthesis of some O-substituted 4-quinolinols and 5,6,7,8-tetrahydro-4-quinolinols 7-13 is described. 2 and 4 afford the 4-chloroquinolines 14 and 15 with POCI3. These can be transformed into 4-aryloxyquinolines 16 and 17 as well as 4-alkyl- or -arylthioquinolines 20 and 4-aminoquinolines 21.
    Notes: Es wird die Synthese einiger O-substituierter 4-Chinolinole und 5,6,7,8-Tetrahydro-4-chinolinole 7-13 beschrieben. Ausgehend von 2 und 4 gelangt man mit POCl3 zu 4-Chlorchinolinen 14 und 15, welche in die 4-Aryloxychinoline 16 und 17 sowie 4-Alkyl-(Aryl-)thiochinoline 20 bzw. 4-Aminochinoline 21 übergeführt werden.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820908
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Synthese des α-Anomeren von ara-7-Desazaguanosin durch Phasentransferglycosylierung  -  Steuerung des Anomerenverhältnisses durch das quartäre Ammoniumsalz (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1634-1642 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the α-Anomer of ara-7-Deazaguanosine via Phase-Transfer Glycosylation  -  Control of Anomer Formation by the Quaternary Ammonium Salt2-Amino-7-(α-D-arabinofuranosyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-on (1), the α-anomer of ara-7-deazaguanosine (2), has been prepared via phase-transfer glycosylation of 4-methoxy-2-methylthio-7H-pyrrolo[2,3-d]pyrimidine (3) with 2,3,5-tri-O-benzyl-1-bromoarabinofuranose (5a/5b). The anomeric control can be achieved by equilibration of the α-halogenose 5a to its β-anomer 5b in the presence of a quaternary ammonium salt. The more reactive 5b results in a preferred α-nucleoside formation of 6b by a SN2-type displacement reaction. Treatment with acid causes ether cleavage of 6b under formation of 7a, subsequent methoxymethylation yields 7b. The methylthio group of 7b was displaced by an acetamino residue by nucleophilic substitution in a molten acetamide/sodium hydride mixture giving 7c. After deacetylation simultaneous removal of the methoxymethyl and benzyl residues took place by treatment of 7d with boron trichloride at - 78°C yielding the crystalline α-nucleoside 1.
    Notes: 2-Amino-7-(α-D-arabinofuranosyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-on (1), das α-Anomer von ara-7-Desazaguanosin (2), wurde durch Phasentransferglycosylierung von 4-Methoxy-2-methylthio-7 H-pyrrolo[2,3-d]pyrimidin (3) mit 2,3,5-Tri-O-benzyl-1-bromarabinofuranose (5a/5b) dargestellt. Eine Anomerensteuerung kann über die äquilibrierung der α-Halogenose 5a zur β-Verbindung 5b durch das quartäre Ammoniumsalz erreicht werden. Das reaktivere 5b führt dann in einem SN2-Mechanismus bevorzugt zum α-Nucleosid 6b. Säurehydrolyse führt zur Etherspaltung bei 6b unter Bildung von 7a; anschließende Methoxymethylierung gibt 7b. Nucleophile Substitution des Methylthiorestes in einer Natriumhydrid/Acetamidschmelze führt zu 7c, das zu 7d deacetyliert wird. Simultane Abspaltung der Methoxymethylgruppe und der Benzylreste mit Bortrichlorid bei  -  78°C führt zum kristallinen α-Nucleosid 1.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820906
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Eine weitere Synthese von (±)-Lycopodin (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1700-1705 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Further Synthesis of (±)-LycopodinThe synthesis of (±)-lycopodin from 2-cyanoethyl-5-methyl-1,3-cyclohexanedione (2b) in six steps is described. An important step is the stereoselective 1,3-annulation reaction of the unsaturated imine 4b with acetone dicarboxylic acid yielding the tricyclic ketone 5b.
    Notes: Die Synthese von (±)-Lycopodin (1) aus 2-Cyanethyl-5-methyl-1,3-cylohexandion (2b) in sechs Stufen wird beschrieben. Ein wichtiger Syntheseschritt ist die stereoselektive 1,3-Anellierung des ungesättigten Imins 4b mit Acetondicarbonsäure zum tricyclischen Keton 5b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Pilzpigmente, 41. Naphthochinon-Farbstoffe aus den Schleimpilzen Trichia floriformis und Metatrichia vesparium (Myxomycetes) (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1722-1729 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fungus Pigments, 4141).  -  Naphthoquinone Pigments from the Slime Moulds Trichia floriformis and Metatrichia vesparium (Myxomycetes)Trichione (1) is the red main pigment of fruiting bodies from the slime mould Trichia floriformis. It contains a 2,5-dihydroxynaphthoquinone chromophore, substituted in position 3 by an unsaturated side chain carrying a terminal hemimalonate moiety. Homotrichione (7) differs by the presence of two additional CH2 groups in the side chain. It co-occurs with arcyriaflavin B (5), arcyriaflavin C (6) and further pigments in Metatrichia vesparium.
    Notes: Die Fruchtkörper des Schleimpilzes Trichia floriformis enthalten als roten Hauptfarbstoff Trichion (1), ein 2,5-Dihydroxynaphthochinon, das in 3-Stellung eine ungesättigte Seitenkette mit terminaler Malonhalbester-Gruppierung trägt. Homotrichion (7) unterscheidet sich nur durch eine um zwei CH2-Gruppen längere Seitenkette. Es kommt neben 1, Arcyriaflavin B und C (5 bzw. 6) und weiteren Farbstoffen in Metatrichia vesparium vor.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820913
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Stereochemische Untersuchungen zur Bildung von Naphtho-[1,2-b]furan-2-onen durch Hydrolyse von α,β-ungesättigten γ, Δ-Epoxysäureestern (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1781-1807 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemical Investigations on the Formation of Naphtho[1,2-b]furan-2-ones by Hydrolysis of α,β-Unsaturated γ,Δ-Epoxy Acid EstersThe α,β-unsaturated epoxy acid esters (E, Z)-12, -13, -30, -35a, and -42 are prepared from the epoxydecalones 8, 9, 25c, 29, and 34 by reaction with methyl (dimethoxyphosphoryl)acetate (14a). The (Z)-acid esters 12, 30, 35a, and 42, separated by column chromatography, give with 2 N H2SO4 in acetone the stereochemically pure naphthofuranones 15, 32, 36, and 43. As expected, hydrolysis of the (E)-acid esters 12, 30, and 35a yields the trans-dihydoxy acid esters 47-49.  -  Hydrolysis of (E, Z)-13 proceeds without stereoselectivity to give the butenolides 19 and 20, and the diol esters (E)-21 and -22.  -  The epoxy (E, Z)-acid esters 12 and 35a are homogeneously hydrogenated to the saturated, epimeric esters 18α/β and 41α/β which are hydolyzed to give the stereoisomeric hydroxylactones 16, 17 and 33, 40. On the other hand, 17, 33, and 40 are also obtained by hydrogenation of the butenolides 15, 32, and 37.
    Notes: Aus den Epoxydecalonen 8, 9, 25c, 29 und 34 werden mit Methyl-(dimethoxyphosphoryl)acetat (14a) die α,β-ungesättigten γ,Δ-Epoxysäureester (E, Z)-12, -13, -30, -35a und -42 dargestellt. Mit 2 N H2SO4 in Aceton werden aus den säulenchromatographisch abgetrennten (Z)-Säureestern 12 30, 35a und 42 die stereochemisch einheitlichen Naphthofuranone 15, 32, 36 und 43 erhalten. Die Hydrolyse der (E)-Säureester 12, 30 und 35a ergibt wie erwartet die trans-Dihydroxysäureester 47-49.  -  Die Hydrolyse von (E, Z)-13 verläuft ohne Stereoselektivität zu den Butenoliden 19 und 20 und den Diol-estern (E)-21 und -22.  -  Die (E, Z)-Epoxysäureester 12 und 35a können zu den gesättigten epimeren Estern 18α/β und 41α/β hydriert werden, deren saure Hydrolyse je zwei stereoisomere Hydroxylactone 16, 17 und 33, 40 liefert. Andererseits können 17, 33 und 40 auch aus den Butenoliden 15, 32 und 37 durch Hydrierung gewonnen werden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821005
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Synthesen biskationischer, trypanocider 1-Benzofuran-Verbindungen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1836-1869 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Biscationic, Trypanocidal 1-Benzofuran Compounds2-Phenyl-1-benzofurans with the substituents Br, NO2, CN, and -NH2, -NH-C(=NH)-NH2, -C(=NH)-NH2, -C=N-CH2-CH2-NH in 4′,5-position were synthesized.  -  For arylated formamidine derivatives [Ar-N=CH-N(CH3)2] a simple new preparation was found by reacting amine hydrochlorides with dimethylformamide in the presence of cyanamide.  -  Based on 5- or 6-cyano-1-benzofuran-2-carboxylates a series of α,ω-bis(1-benzofuran-2-yl) derivatives with cyano-, amidino-, or imidazolinyl groups in 5- or 6-position was prepared.
    Notes: 2-Phenyl-1-benzofurane mit den Substituenten Br, NO2 sowie CN und -NH2, -NH-C(=NH)-NH2, -C(=NH)-NH2 sowie -C=N-CH2-CH2-NH in 4′,5-Stellung wurden synthetisiert.  -  Für arylierte Formamidin-Derivate [Ar-N=CH-(CH3)2] fand sich in der Umsetzung von Aminhydrochloriden mit Dimethylformamid in Gegenwart von Cyanamid ein einfaches, neues Herstellungsverfahren.  -  Auf der Basis von 5- oder 6-Cyan-1-benzofuran-2-carbonsäureester konnte eine Serie von α,ω-Bis(1-benzofuran-2-yl)-Derivaten mit Cyan- oder Amidino- oder Imidazolinyl-Gruppen in 5- oder 6-Stellung dargestellt werden.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Enhydrazine, 32. Ein Zugang zu 3-Hydroxymethyl-1,5,6,7-tetrahydro-4H-indazol-4-onen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1891-1896 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 32.  -  An Access to 3-Hydroxymethyl-1,5,6,7-tetrahydro-4H-indazol-4-ones5-Methyl-1,3-cyclohexanedione is C-acylated with benzyloxyacetimidazolide to yield 2b which with hydrazines gives the 1,5,6,7-tetrahydro-4H-indazol-4-ones 3a-d. Hydrogenolysis leads to the title compounds 4a-d. The acetate 5a from 3d is hydrogenolyzed to give 5b and is further transformed into the carbamate 6.
    Notes: 5-Methyl-1,3-cyclohexandion wird von Benzyloxyessigsäure-imidazolid zu 2b C-acyliert, das mit Hydrazinen die 1,5,6,7-Tetrahydro-4H-indazol-4-one 3a-d ergibt. Deren Hydrogenolyse führt zu den Titelverbindungen 4a-d. Das Acetat 5a aus 3d wird zu 5b hydrogenolysiert und weiter in das Carbamat 6 umgewandelt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821010
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Partialsynthese des “Sargasterols” und des (20S)-Cholesterols (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1897-1906 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Partial Synthesis of “Sargastero” and (20S)-CholesterolThe data of the synthetic (20S)-3β-hydroxy-5-cholesten-24-one (5b) and its acetate 5a differ significantly from those given for the degradation product of “Sargastero”. The compounds 5a, b were converted into the E, Z-isomeric (20S)-stigmasta-5,24(28)-dien-3β-ols 8b, 9b, into their acetates 8a, 9a, and into (20S)-cholesterol (10b). (20S)-cholesterol acetate (10a) shows a lower melting point than that which is given in literature.
    Notes: Die Eigenschaften des synthetischen (20S)-3β-Hydroxy-5-cholesten-24-ons (5b) und seines Acetats 5a unterscheiden sich signifikant von den für das Abbauprodukt des “Sargasterols” beschriebenen. Aus 5a, b wurden die E, Z-isomeren (20S)-Stigmasta-5,24(28)-dien-3β-ole 8b, 9b und ihre Acetate 8a, 9a sowie das (20S)-Cholesterol (10b) dargestellt. (20S)-Cholesterolacetat (10a) zeigt einen tieferen Schmelzpunkt als in der Literatur angegeben.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821011
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Darstellung von 4,6-Diaminozuckern aus Hex-2-enosen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1920-1923 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of 4,6-Diamino Sugars via Hex-2-enonesThe synthesis and structure determination of 4,6-diaminohexoses from glycals via 2-eno sugars, SN reaction with NaN3, and final reduction is described.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821013
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Masthead (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    4-Amino-7-(rac-2,3-dihydroxypropyl)-7H-pyrrolo′l2,3-d]-pyrimidin  -  Synthese von Acyclotubercidin (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1940-1945 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 4-Amino-7-(rac-2,3-dihydroxypropyl)-7H-pyrrolo[2,3-d]pyrimidine  -  Synthesis of AcyclotubercidinAlkylation of the aglycone 4a with the tosylate 5b under phase transfer conditions in the presence of tetrabutylammonium hydrogen sulfate yields regioselectively the N-7 derivative 6a. Using benzyltriethylammonium chloride instead of the tetrabutylammonium salt as phase transfer catalyst the benzyl group of the catalyst is transferred to N-7 of the heterocycle 4a. After desulfurization and removal of the isopropylidene protecting group compound 3b was obtained. The latter represents an isosteric analogue of the antivirally active acyclonucleoside 2.
    Notes: Durch Phasentransfer-Alkylierung des Aglycons 4a mit dem Tosylat 5b in Gegenwart von Tetrabutylammoniumhydrogensulfat kann regioselektiv das N-7-Verknüpfungsprodukt 6a dargestellt werden. Wird die Reaktion in Gegenwart von Benzyltriethylammoniumchlorid als Phasentransfer-Katalysator durchgeführt, so erfolgt die übertragung des Benzylrestes vom Katalysator auf N-7 des Heterocyclus 4a. Das geschützte Acyclonucleosid 6a kann nach Entschwefeln und Abspalten der Isopropyliden-Schutzgruppe in 3b übergeführt werden. Verbindung 3b stellt ein Isoster des antiviral wirksamen Acyclonucleosids 2 dar.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Asymmetrische Synthesen über heterocyclische Zwischenstufen, XVI. Enantioselektive Synthese von α-Alkyl-α-phenylglycinen durch Alkylieren von an C-6 chiral substituierten 3,6-Dihydro-3-phenyl-2H-1,4-oxazin-2-onen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1952-1970 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses via Heterocyclic Intermediates, XVI1).  -  Enantioselective Synthesis of α-Alkyl-α-phenylglycines by Alkylation of 3,6-Dihydro-3-phenyl-2H-1,4-oxazin-2-ones Chirally Substituted at C-63,6-Dihydro-3-phenyl-2H-1,4-oxazin-2-ones 3 are synthesized from DL-phenylglycine and (S)-2-hydroxyalkanoic acids 4. The heterocycles 3 contain an endocyclic chiral center at C-6. The anions 10 of 3 react with alkyl halides in good chemical yields and with d. e. values from 50 up to more than 95% (asymmetric induction) to give the adducts 11. On hydrolysis of 11 the 2-hydroxy-alkanoic acids 4 and the optically active (S)-α-alkyl-α-phenylglycines 14 are liberated.
    Notes: Ausgehend von DL-Phenylglycin und (S)-2-Hydroxyalkansäuren 4 werden die 3,6-Dihydro-3-phenyl-2H-1,4-oxazin-2-one 3 aufgebaut, die an C-6 ein endocyclisches Chiralitätszentrum besitzen. Die Anionen 10 von 3 reagieren mit Alkylhalogeniden an C-3 mit guten chemischen Ausbeuten und mit 50 bis mehr als 95% d. e. (asymmetrische Induktion). Bei der Hydrolyse der Addukte 11 werden die 2-Hydroxyalkansäuren 4 und die optisch aktiven (S)-α-Alkyl-α-phenylglycine 14 freigesetzt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Optical resolution of racemic S-(Carboxymethyl)cysteine (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1995-1998 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Racematspaltung von S-(Carboxymethyl)cysteinRacemisches S-(Carboxymethyl)cystein [(R, S)-2] wird in das Ammoniumsalz (R, S)-3 übergeführt, das nach Herstellung einer übersättigten Lösung und Animpfen mit (R)- oder (S)-3 durch fraktionierende Kristallisation gespalten werden kann. (R, S)-2 bildet mit optisch aktiven Aminen diastereomere Salze, die leicht trennbar sind und so ebenfalls eine Racematspaltung erlauben. So erhält man mit (1R,2S)-2-Amino-1-phenyl-1-propanol (4) optisch reines (R)-S-(Carboxymethyl)-cystein [(R)-2] in 93proz. Ausbeute. Die Racematspaltung von (R, S)-2 ist auch mit Hilfe von (R)-1-Phenylethylamin (5) möglich.
    Notes: Racemic S-(carboxymethyl)cysteine [(R, S)-2] obtained from racemic cysteine is resolved via its ammonium salt (R, S)-3 by preferential crystallization procedure. Furthermore, (R, S)-2 forms with optically active amines separable, diastereomeric salts. Thus, (1R,2S)-2-amino-1-phenyl-1-propanol (4) affords optically pure (R)-S-(carboxymethyl)cysteine [(R)-2] in 93% yield. The resolution of (R, S)-2 is also possible with (R)-1-phenylethylamine (5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Asymmetrische Totalsynthese von 19-Nor-Steroiden mit photochemischer Schlüsselreaktion: Enantiomerenreine Zielverbindungen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1999-2040 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Total Synthesis of 19-Nor-Steroids via a Photochemical Key Reaction: Enantiomerically Pure Target CompoundsA total synthesis of the enantiomerically pure 19-nor-steroids estrone (1a), 19-norandrost-4-en-3,17-dione (2a), estradiol-17β (3a), and 19-nortestosterone (4a) is described. It follows the A + D→AD→ABCD sequence, proceeds via a kinetically unstable o-quinodimethane derivative obtained in a light induced reaction, and employs the chiral synthetic building block dimethyl (R)-2-vinyl-1,1-cyclopropanedicarboxylate (12b). The latter is easily accessible by an asymmetry inducing ScN′ reaction. During the synthetic procedure it is isolated enantiomerically pure. The analytic procedure reveals that 12b is formed with an optical purity or an enantiomeric excess, respectively, of 95%.
    Notes: Eine Totalsynthese der enantiomerenreinen 19-Nor-Steroide Östron (1a), 19-Norandrost-4-en-3,17-dion (2a), östradiol-17β (3a) und 19-Nortestosteron (4a) wird beschrieben. Sie folgt dem A + D→AD→ABCD-Aufbauprinzip, durchläuft ein lichtinduziertes, kinetisch instabiles o-Chinodimethan-Derivat und verwendet den chiralen Synthesebaustein (R)-2-Vinyl-1,1-cyclopropan-dicarbonsäure-dimethylester (12b). 12b ist durch eine Asymmetrie induzierende ScN′-Reaktion (s. Abb. 2) bequem zugänglich. Bei der Synthese fällt 12b enantiomerenrein an. Das analytische Procedere offenbart, daß 12b mit einer optischen Reinheit oder mit einem Enantiomeren-überschuß jeweils von 95% zustande kommt.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Oniumsalz-katalysierte Acylierungen mit Diketen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2062-2067 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Onium Salt-catalyzed Acylations with DiketeneWeak NH- and CH-acids can be acylated advantageously by diketene (1) in the presence of a quaternary ammonium chloride. Carboxamides yield with one or two moles of 1 the products 3 or 10 selectively. β-Keto esters and β-diketones lead to 12a, b or 13, respectively, and acetoacetamides give 5 or 8. The polymer 16 and/or 17 is formed by self-condensation of 1.
    Notes: Schwache NH- und CH-Säuren können mit Diketen (1) vorteilhaft in Gegenwart eines quartären Ammoniumchlorids acyliert werden. Carbonsäureamide liefern wahlweise mit einem oder zwei Mol 1 die Produkte 3 bzw. 10. β-Ketoester und β-Diketone ergeben 12a, b bzw. 13, Amide der Acetessigsäure führen zu 5 oder 8. Bei der Selbstkondensation von 1 entstehen das Polymer 16 und/oder 17.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Synthese des Lycopodium-Alkaloids (±)-Acetylflabellidin über 1,3-Anellierung von Eniminen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2057-2061 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the Lycopodium Alkaloid (±)-Acetylflabellidine via 1,3-Annulation Reactions of EniminesThe 1,3-annulation reaction of 2,3,4,5-tetrahydro-6-methylpyridine (11) with the enimine 7 catalyzed by perchloric acid and subsequent acetylation stereoselectively yield the tetracyclic adduct 2 as the main product, the structure and relative configuration of which are in agreement with the acetyl derivative of the Lycopodium alkaloid flabellidine (1).
    Notes: Die durch Perchlorsäure katalysierte 1,3-Anellierung von 2,3,4,5-Tetrahydro-6-methylpyridin (11) an das Enimin 7 mit anschließender Acetylierung liefert in stereoselektiver Reaktion als Hauptprodukt das tetracyclische Addukt 2, dessen Struktur und relative Konfiguration mit dem Acetylderivat des Lycopodium-Alkaloids Flabellidin (1) identisch ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Synthese sterisch gehinderter Peptide und Depsipeptide nach einem Säurechlorid-Verfahren mit 2-Phosphonioethoxycarbonyl-(Peoc-)Aminosäuren und -Hydroxysäuren (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2068-2078 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Sterically Hindered Peptides and Depsipeptides by Means of an Acid Chloride Procedure with 2-Phosphonioethoxycarbonyl (Peoc) Amino Acids and Hydroxy Acids2-(Triphenylphosphonio)ethoxycarbonyl (Peoc) amino acids 1 and hydroxy acids 5 are converted by treatment with oxalyl chloride into the corresponding acid chlorides 2 and 6 which are stable at room temperature. Sterically hindered amide bonds, for instance the blocked valine peptides 3a - g and hydroxyacyl dipeptides 7, can be synthesized using these activated compounds. In this manner sporidesmolic acid B (9a) is obtained from its fully protected form 7a; the former being identical in its properties with the degradation product of sporidesmolide I. In this procedure no razemisation takes place although the acid chloride condensation was applied twice in succession.
    Notes: 2-(Triphenylphosphonio)ethoxycarbonyl-(Peoc-)aminosäuren 1 und -hydroxysäuren 5 werden mit Oxalylchlorid in bei Raumtemp. stabile Säurechloride 2 bzw. 6 übergeführt. Mit diesen aktivierten Verbindungen werden sterisch gehinderte Amidbindungen  -  z. B. in den geschützten Valin-Peptiden 3a - g und in Hydroxyacyl-Dipeptiden 7  -  hergestellt. Nach Schutzgruppenabspaltung aus der voll geschützten Form 7a entsteht so die Sporidesmolsäure B (9a), die in ihren Eigenschaften mit dem Abbauprodukt aus dem Sporidesmolid I übereinstimmt. Trotz zweimaliger Anwendung der Säurechlorid-Kondensation ist keine Racemisierung eingetreten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Synthese von 5H,5′H-5,5′-(2-Buten-1,4-diyliden)bis[furan-2-on] (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2096-2097 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 5H,5′H-5,5′-(2-Buten-1,4-diyliden)bis[furan-2-one]Reaction of 2,5-dihydro-2,5-dimethoxyfuran with trimethylchlorsilane affords cis-5H,5′H-5,5′-(2-buten-1,4-diyliden)bis[furan-2-one] (2)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Syntheses of 3-Cyanopropan- and 4-Aminobutanamides (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2098-2102 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesen von 3-Cyanpropan- und 4-AminobutanamidenDie 3-Cyanpropanamide 5a - g werden aus Propenamiden und Blausäure oder aus 3-Cyanpropanoylverbindungen nach den Methoden A - D dargestellt. Hydrierung von 5a - d, g liefert die 4-Aminobutanamide 2a - d, g.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821119
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Masthead (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    1,3-Dipolare Cycloadditionen von Azomethin-yliden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2146-2152 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Dipolar Cycloadditions of Azomethine Ylides1,3-Dipolar cycloadditions of the azomethine ylides 2 and 9 with Schiff′s bases have been investigated. Depending on the structures of both the dipolarophiles and the dipoles, cycloadducts of “exo” and/or “endo” type were formed.
    Notes: Die 1,3-dipolaren Cycloadditionen der Azomethin-ylide 2 und 9 mit Schiffschen Basen wurden untersucht. Es bilden sich Cycloaddukte vom “exo”-und/oder “endo”-Typ in Abhängigkeit von der Struktur des Dipolarophils und des Dipols.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Synthesen von Peptidalkaloiden, VI. über Aminosäuren und Peptide, XXXVII. Totalsynthese von 9,10-Dihydrozizyphin G (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2153-2162 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Peptide Alkaloids, VI1a).  -  Amino Acids and Peptides, XXXVII1b).  -  Total Synthesis of 9,10-Dihydrozizyphine G9,10-Dihydrozizyphine G (2a) was synthesized according to the reaction sequence 3a → 4a → 5a → 6a → 7a → 8a → 9a → 2a by ring formation at the phenylethylamine nitrogen atom and by the sequence 3a → 10a → 11a → 12a → 2a forming the ring at the proline nitrogen. The last method was more advantageous. The ring closures were achieved by catalytic hydrogenation of the pentafluorophenyl esters of ω-Z-amino acids.
    Notes: 9,10-Dihydrozizyphin G (2a) wurde auf dem Wege 3a → 4a → 5a → 6a → 7a → 8a → 9a → 2a durch Ringschluß am Phenylethylaminstickstoff (C) und über die Sequenz 3a → 10a → 11a → 12a → 2a durch Ringbildung am Prolinstickstoff synthetisiert. Der letzte Weg erwies sich als günstiger. Die Ringschlüsse wurden mittels katalytischer Hydrierung der ω-Z-Aminosäure-penta-fluorphenylester erreicht.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Carboxonium-Ionen-Reaktionen cyclischer Acetale, VII Synthese von rac-4,5,6,7-Tetrahydro-3,5-dimethyl-1-benzofuran sowie eines Gemisches seiner 3,4- und 3,6-Dimethylisomeren (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2163-2171 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Carboxonium Ions of Cyclic Acetals, VII1).  -  Synthesis of rac-4,5,6,7-Tetrahydro-3,5-dimethyl-1-benzofuran and of a Mixture of its 3,4- and 3,6-Dimethyl IsomersThermolysis of the 4-methylene-1,3-dioxolanes 4 or of the β-oxa-γ,δ-enones 6 leads in the presence of protons to rac-4,5,6,7-tetrahydro-3,5-dimethyl-1-benzofuran (5a) and to a mixture of its 3,4- and 3,6-dimethyl isomers 5b/5c. The mechanism of the furan formation has been investigated.
    Notes: Durch Thermolyse der 4-Methylen-1,3-dioxolane 4 oder der β-Oxa-γ,δ-enone 6 entstehen in Gegenwart von Protonen rac-4,5,6,7-Tetrahydro-3,5-dimethyl-1-benzofuran (5a) sowie ein Gemisch von dessen 3,4- und 3,6-Dimethylisomeren 5b/5c. Der Mechanismus der Furanbildung wird untersucht.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Chemie der 2,3-Dihydro-2,3-diminofurane (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 2178-2188 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Chemistry of 2,3-Dihydro-2,3-diiminofuransThe title compounds 6 undergo with nucleophiles condensation reactions in position 3, or ring opening and rearrangements to yield 2,3-furandiones 2, 2,3-pyrrolediones 3 as well as the 3-oxime, 3-imine and 3-hydrazone derivatives 5, 10, 11, 15 of these compounds, furthermore 3-butenamides 8, and 5- or 3-pyrazolecarboxamides 13, 14. With heterocumulenes 19, 21, and thioglycolic acid (18), mostly [2 + 2] cycloadditions or 2,3-cyclocondensations, respectively, take place at the β-imino group only, leading to spiro[azetidine-2,3′(2′H)-furans] 23, spiro[furan-3(2H),2′-[2H-1,3,5]-thiadiazines] 20, the spiro[3H-pyrrole-3,2′-[1,3]thiazolidine] 17, and the spiro[furan-2(3H),2′-[1,3]thiazolidine] 26. By a [4 + 2] cycloaddition involving both imino groups the furo[2,3-b]pyrazine 25 is formed. These ring systems have not yet been described.
    Notes: Die Titelverbindungen 6 gehen mit Nucleophilen Kondensationsreaktionen in der 3-Stellung ein, oder reagieren unter Ringöffnung und -umlagerung, wobei 2,3-Furandione 2, 2,3-Pyrroldione 3 sowie die 3-Oxime, 3-Imine und 3-Hydrazone 5, 10, 11, 15 dieser Verbindungen und weiterhin 3-Butenamide 8 und 5- bzw. 3-Pyrazolcarboxamide 13, 14 gebildet werden. Mit Heterokumule-nen 19, 21 und Thioglycolsäure (18) erfolgen meist [2 + 2]-Cycloadditionen bzw. 2,3-Cyclokondensationen nur an der β-Iminogruppe, die zu Spiro[azetidin-2,3′(2′-H)-furanen] 23, Spiro[furan-3(2H),2′-[2H-1,3,5]thiadiazinen] 20, dem Spiro[3H-pyrrol-3,2′-[1,3]thiazolidin) 17 und dem Spiro[furan-2(3H),2′-[1,3]thiazolidin] 26 führen. In einer [4 + 2]-Cycloaddition unter Beteiligung beider Iminogruppen wird das Furo[2,3-b]pyrazin 24 gebildet. Diese Ringsysteme sind noch nicht beschrieben worden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Strukturelle Abwandlungen an partiell silylierten Kohlenhydraten, 61) Transformationen an N-Acetylneuraminsäure (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1-13 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structural Modifications of Partially Silylated Carbohydrates by Means of Triphenylphosphane and Azodicarboxylate, 61). - Transformations with N-Acetylneuraminic AcidFrom methyl 5-acetylamino-3,5-dideoxy-D-glycero-β-D-galacto-2-nonulopyranosidonic acid methyl esters 1 the 9-O-, 4,9-bis-O-, or 4,8,9-tris-O-(tert-butyldimethylsilyl)nonulopyranosidonic acid methyl ester derivatives 1a,1b,and were obtained 1e (Scheme 1). Treatment of 1c with acetanhydride/pyridine yields 1d which is converted into 1i with migration of one acyl group by means of tetrabutylammonium fluoride. Transformation of 1i with triphenylphosphane/diethylazodicarboxylate/hydrazoic acid (TPP/DEAD/HN,) yields a mixture of 9-azido-9-deoxy-o-glycero-p-D-galacto- and 8-azido-8-deoxy-1.-glycero-β-D-galacto-2-nonulopyranosidonic acid methyl ester derivatives 2 and 3 (Scheme 2). 1c can be transformed with triphenylphosphane(TPP) and diethyl azodicarboxylate (DEAD) to the 7,8-anhydrononulopyranosidonic acid methylester derivatives 4 and 5. Compound 5 can be converted with NaN,/NH,CI to the 5-acetylamino-8-azido-8-deoxyneuraminic acid derivative 6a (Scheme 3). Reaction of 1e with TPP/DEAD/HN, affords under 1.3-neighbouring group participation methyl 4,8,9-tris-O-(tert-butyldimethylsilyl)-3,5-d∼deoxy-5-(5-methyl-l-tetrazolyl)-D-glycero-β-D-altro-2-nonulopyranosidonic acid methyl ester (7a) (Scheme 4).
    Notes: Aus den Methyl-5-acetylamino-3,5-didesoxy-D-glycero-β-D-galakto-nonulopyranosidonsäure-methylestern 1 wurden die 9-O-, 4,9-Bis-O- und 4,8,9-Tris-O-(tert-butyldimethylsilyl)etherderivate 1a, 1c und 1e hergestellt (Schema 1). Das aus 1c gewonnene 7,8-Diacetylderivat 1d geht mit Tetrabutylammoniumfluorid unter Verlust einer Silylgruppe und Acetylwanderung in 1i über. Letzteres liefert mit Triphenylphosphan/Azodicarbonsäure-diethylester/Stickstoffwasserstoffsäure (TPP/DEAD/HN3) ein Gemisch aus den 9-Azido-9-desoxy-D-glycero-β-D-galakto- und 8-Azido-8-desoxy-L-glycero-β-D-galakto-2-nonulosonsäurederivaten 2 und 3 (Schema 2). Aus 1c erhält man mit Triphenylphosphan/Azodicarbonsäure-diethylester (TPP/DEAD) die 7,8-Anhydrononulosonsäurederivate 4 und 5; letzteres wurde mit NaN3 und NH4Cl in das 5-Acetylamino-8-azido-8-desoxyneuraminsäurederivat 6a übergeführt (Schema 3). Setzt man 1e mit TPP/DEAD/HN3 um, so erhält man als Folge einer 1,3-Nachbargruppenreaktion der 5-Acetylaminogruppe den Methyl-4,8,9-tris-O-(/er/-butyldimethylsilyl)-3,5-didesoxy-5-(5-methyl-1-tetrazolyl)-D-glycero-β-L-altro-2-nonulopyranosidonsäure-methylester (7a) (Schema 4).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Reduktion von 3-Amino-1,2-benzisothiazolen und 3-Imino-1,2-benzisothiazolinen zu 2-Mercaptobenzamidinen, Benz-amidiniumthiolaten oder 1,2-BenzothiochinonmethidenHerrn Prof. Dr. Herbert Grünewald zum 60. Geburtstag gewidmet. (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 14-27 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reduction of 3-Amino-1,2-benzisothiazoles and 3-Imino-1,2-benzisothiazolines to 2-Mercapto-benzamidines, Benzamidiniumthiolates, or 1,2-Benzothioquinone MethidesThe 2-mercaptobenzamidines 4 are formed by reduction of the 3-amino-1,2-benzisothiazoles 1 or 3-imino-1,2-benzisothiazolines 2. They can be described as 2-mercaptobenzamidines 4, benzamidiniumthiolates 4′, and 1,2-benzothioquinone methides 4″ (a canonical form in the resonance hybrid 4′ ++ 4″). Which structure is most accurate depends on the spatial requirements of the substituents R1, R2, and R3 and is deduced from spectroscopic studies. The steric arrangements of these groups in the amidinium structure (E or Z) have been determined.
    Notes: Durch Reduktion der 3-Amino-1,2-benzisothiazole 1 oder 3-Imino-1,2-benzisothiazoline 2 entstehen die 2-Mercaptobenzamidine 4. Ihre Struktur kann als 2-Mercaptobenzamidin 4, mesoionisches Benzamidiniumthiolat 4′ oder 1,2-Benzothiochinonmethid 4″ (eine Grenzstruktur im Resonanzhybrid 4′ ++ 4″) beschrieben werden. Welcher Struktur das größere Gewicht zukommt, hängt von der Raumbeanspruchung der Substituenten R1, R2 und R3 ab. Die sterischen Anordnungen dieser Reste in der Amidiniumstruktur (E bzw. Z) wurden bestimmt.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Synthese von Hydroxy-γ-lactonen aus α,β-ungesättigten Aldehyden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 49-67 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Hydroxy-γ-lactones from α,β-Unsaturated AldehydesAccording to Scheme 1 the α,β-unsaturated aldehydes 3-9 react in three steps (epoxidation, PO olefination, and selective hydrogenation) to give the epoxy esters 36-42. Generally, these esters are interchangeable, predominantly the epoxidation and olefination. Thus, the epoxy acid esters 26-32 are synthesized via the epoxides 10-16 or via the dienoic esters 17-23. Homogeneously catalyzed hydrogenation of 26-31 gives the saturated esters 36-41. In case this reaction fails (e. g. with 32), sequence e, g (Scheme 1) via γ,δ-unsaturated esters (e. g. 35) might be successful. All these α,β-unsaturated esters 17-23 and 26-32 possess (E) configuration. Even the reaction of 3 or 6 with the propionate 2 leads to the (E) esters 24 or 25, respectively. Hydrolysis of the epoxy acid esters 36-41 gives the hydroxy-γ-lactones 43-48.
    Notes: Gemäß Schema 1 werden die α,β-ungesättigte Aldehyde 3-9 in drei Stufen (Epoxidierung, PO-Olefinierung und selektive Hydrierung) zu den Epoxysäureestern 36-42 umgesetzt. Im allgemeinen sind diese Stufen vertauschbar, besonders Epoxidierung und Olefinierung. So können die Epoxysäureester 26-32 über die Epoxide 10-16 oder die Diensäureester 17-23 dargestellt werden. Hydrierung von 26-31 mit homogener Katalyse ergibt die gesättigten Ester 36-41. Bei Versagen dieser Reaktion (z. B. bei 32) kann auf die Folge e, g (Schema 1) über die γ,δ-ungesättigten Ester (z. B. 35) ausgewichen werden. Die α,β-ungesättigten Ester 17-23 und 26-32 besitzen (E)-Konfiguration. Auch mit dem Propionat 2 ergeben 3 oder 6 die (E)-Säureester 24 bzw. 25. Hydrolyse der Epoxysäureester 36-41 führt zu den Hydroxy-γ-lactonen 43-48.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Terpene und Terpenderivate, XIII1) Synthese von (±)-8,9-Dehydroasterolid (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 73-79 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Terpenes and Terpene Derivatives, XIII1). - Synthesis of (±)-8,9-DehydroasterolideFrom the ketoester 2 the α,β-unsaturated ketone 9 is prepared via ketalization (→ 3), hydroboration (→ 4), oxidation (→ 6), Wittig reaction (→ 7), hydrolysis (→ 8a), and oxidative decarboxylation. 9 is a useful starting material for the synthesis of 8,9-dehydroasterolide (1) via epoxidation (→ 10), PO olefination (→ 11, hydrolysis (→ 12), and dehydratization.
    Notes: Aus dem Ketoester 2 wird durch Ketalisierung (→ 3), Hydroborierung (→ 4), Oxidation (→ 6), Wittig-Reaktion (→ 7), Hydrolyse (→ 8a) und oxidative Decarboxylierung das α,β-ungesättigte Keton 9 dargestellt. Daraus wird durch Epoxidierung (→ 10), PO-Olefinierung (→ 11), Hydrolyse (→ 12) und Dehydratisierung 8,9-Dehydroasterolid (1) erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Reaktionen von Allylidenphosphoranen mit Heterokumulenen, I. Vinylketenimine (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 80-86 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Allylidenephosphoranes with Heterocumulenes, I. - VinylketeniminesAccording to their α-substituent the allylidenephosphoranes 4 are converted by isocyanates either via Wittig reaction into the hitherto little known vinylketenimines 7 or by carbamoylation and ring closure into the pyrrolone 5 or the 3-pyridylidenephosphoranes 9, a new stable ylide series. 7 reacts with electron deficient dienophils in a [4 + 2] cycloaddition to yield 10 or 11, respectively.
    Notes: Die Allylidenphosphorane 4 bilden mit Isocyanaten in Abhängigkeit des α-Substituenten entweder durch Wittig-Reaktion die wenig bekannten Vinylketenimine 7 oder durch Carbamoylierung und Ringschluß das Pyrrolon 5 bzw. die 3-Pyridylidenphosphorane 9, eine neue stabile Ylidreihe. 7 geht mit elektronenarmen Dienophilen [4 + 2]-Cycloaddition zu 10 bzw. 11 ein.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    2,2,4-Trisubstituted 2H-1,3-Oxazetes - A New Type of Heterocycles - A Reinvestigation (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 231-239 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 2,2,4-Trisubstituierte 2H-1,3-Oxazete - Ein neuer Typ von Heterocyclen - Eine KlarstellungEs wird gezeigt, daß die kürzlich beschriebene Reaktion von Lithiumhydrid mit Additionsprodukten aus Acylisothiocyanaten und Aminen, Methanol, sowie Methanthiol in DMF und nachfolgende Methylierung nicht zu neuen Heterocyclen - den 2,2,4-trisubstituierten 2H-1,3-Oxazeten - führt, sondern N-Acylisothioharnstoffe, N-Acylmono- und -dithioisocarbamate ergibt. Deren Strukturen werden durch IR-, Massen-, 1H-NMR- und 13C-NMR-Spektren bestätigt.
    Notes: The recently described reaction between lithium hydride and addition products of acyl isothio-cyanates with amines, methanol, and methanethiol in DMF followed by alkylation with methyl iodide is shown not to generate a new class of heterocycles - 2,2,4-trisubstituted 2H-1,3-oxazetes - but to yield N-acyl isothioureas, N-acyl mono-, and -dithioisocarbamates, respectively. The structures are confirmed by IR, mass, 1H-NMR, and 13C-NMR spectra.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Reaktionen von Cyanidionen mit α,β-ungesättigten Estern, IV1,2,3) Reaktionen zum Aufbau von Carbocyclen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 240-249 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyanide Ions with α,β-Unsaturated Esters, IV1,2,3). - Reactions to CarbocyclesSodium cyanide reacts with diethyl 2-methylenealkanedioates 1a-c and 8a-h to give simple or alkylated ethyl 2-cyano-3-oxo-1-cycloalkanecarboxylates 5a-c and 9a-h, respectively. From these the 3-oxo-1-cycloalkanecarboxylic acids 6a-c and 10a-h, respectively, and the methyl esters 11a-h are obtained. Analogously α,β-unsaturated dicarboxylates such as 12a, b lead to ethyl 2-cyano-2-methyl-5-oxo-1-cyclopentanecarboxylate (13a) and ethyl 2-cyano-2-methyl-6-oxo-1-cyclohexanecarboxylate (13b), respectively.
    Notes: Einwirkung von Natriumcyanid auf 2-Methylenalkandisäure-diethylester 1a-c und 8a-h führt zu einfachen bzw. alkylierten 2-Cyan-3-oxo-1-cycloalkancarbonsäure-ethylestern 5a-c und 9a-h. Daraus erhält man die 3-Oxo-1-cycloalkancarbonsäuren 6a-c und 10a-h sowie die Methylester 11a-h. Analog reagieren α,β-ungesättigte Dicarbonsäureester wie 12a, b zum 2-Cyan-2-methyl-5-oxo-1-cyclopentancarbonsäure-ethylester (13a) bzw. 2-Cyan-2-methyl-6-oxo-1-cyclo-hexancarbonsäure-ethylester (13b).
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Reaktionen mit Cyclobutendionen, LXII. 3-(α-Bromalkyl)-4-phenylcyclobuten-1,2-dione (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 396-405 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclobutenediones, LXII1).  -  3-(α-Bromoalkyl)-4-phenylcyclobutene-1,2-dionesBromination of 3-alkyl-4-phenylcyclobutene-1,2-dione 1a-c leads to the title compounds 2a-c and 4 which react with C, O, and S nucleophiles to yield the substitution products 3a-r, 5a, and 5b. Hydrolysis of the acylal 5a furnishes the ring enlarged structure 7. With hydrogen sulfide 2a, b are converted into the dispiro compounds 9a, b. Reaction of 2a with the thiocarbonyl compounds 11a-d affords the salts 12a-d from which 12c and 12d can be degraded to give the (β-anilinoalkenyl)cyclobutenediones 13a and b.
    Notes: Die 3-Alkyl-4-phenylcyclobuten-1,2-dione 1a-c werden zu den Titelverbindungen 2a-c und 4 bromiert. Diese reagieren mit C-, O- und S-Nucleophilen zu den Substitutionsprodukten 3a-r, 5a und 5b. Das Acylal 5a wird hydrolytisch zum Fünfring 7 erweitert. Mit Schwefelwasserstoff werden 2a, b zu den Dispiro-Verbindungen 9a, b umgewandelt. Die Thiocarbonylverbindungen 11a-d bilden mit 2a die Salze 12a-d. Von diesen werden 12c und 12d zu den (β-Anilinoalkenyl)cyclobutendionen 13a und b abgebaut.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Enhydrazine, 31. Synthese von 2,3-Dihydro-1H-pyrazolo[1,2-a]pyrazol-4-iumsalzen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 420-430 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 311).  -  Synthesis of 2,3-Dihydro-1H-pyrazolo[1,2-a]pyrazol-4-ium SaltsThe preparation of the 1-[3-(p-tolylsulfonyloxy)propyl]pyrazoles 1c, 3c, 7e, and 11d, e is described. They easily suffer cyclization (in some cases spontaneously) to the 2,3-dihydro-1H-pyrazolo[1,2-a]pyrazol-4-ium tosylates 2b, 4b, 9, and 12a, b of which 12b possesses a constitution similar to that of mitomycin C.
    Notes: Die Darstellung der 1-[3-(p-Tolylsulfonyloxy)propyl]pyrazole 1c, 3c, 7e und 11d, e wird beschrieben. Sie gehen leicht (z. T. spontan) Ringschluß zu den 2,3-Dihydro-1H-pyrazolo[1,2-a]-pyrazol-4-ium-tosylaten 2b, 4b, 9 und 12a, b ein, von denen 12b eine dem Mitomycin C ähnliche Konstitution besitzt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Synthese geschützter N-Nitroso-Zuckeraminosäuren. N-(1,3,4,6-Tetra-O-acetyl-2-desoxy-β-D-glucopyranos-2-yl)-aminosäure-methylester und -β-D-galactopyranos-2-yl)aminosäure-methylester sowie deren N-Nitroso-Derivate (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 780-793 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Protected N-Nitroso Sugar Amino Acids.  -  N-(1,3,4,6-Tetra-O-acetyl-2-deoxy-β-D-glucopyranos-2-yl) Amino Acid Methyl Esters and -β-D-galactopyranos-2-yl) Amino Acid Methyl Esters and Their N-Nitroso DerivativesReacting 1,3,4,6-tetra-O-acetyl-β-D-glucosamine hydrochloride (1) or 1,3,4,6-tetra-O-acetyl-β-D-galactosamine hydrochloride (10) with methyl bromocarboxylates in refluxing acetone in the presence of sodium hydrogen carbonate results in the formation of N-(1,3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucopyranos-2-yl) amino acid methyl esters 2-5 and -β-D-galactopyranos-2-yl) amino acid methyl esters 11-12. Nitrosation of these derivatives of sugar amino acids with dinitrogen trioxide in chloroform at 0°C leads to the derivatives of N-nitroso sugar amino acids 6-9 and 13-14.
    Notes: Durch Umsetzung von 1,3,4,6-Tetra-O-acetyl-β-D-glucosamin-hydrochlorid (1) oder 1,3,4,6-Tetra-O-acetyl-β-D-galactosamin-hydrochlorid (10) mit Bromcarbonsäure-methylestern in siedendem Aceton in Gegenwart von Natriumhydrogencarbonat als Base werden die N-(1,3,4,6-Tetra-O-acetyl-2-desoxy-β-D-glucopyranos-2-yl)aminosäure-methylester 2-5 und -β-D-galactopyranos-2-yl)aminosäure-methylester 11-12 erhalten. Nitrosierung der Zuckeraminosäure-Derivate mit Distickstofftrioxid in Chloroform bei 0°C führt zu den N-Nitroso-Zuckeraminosäure-Derivate 6-9 und 13-14.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820419
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    2-Methylthio-7-desazainosin und sein α-Anomer  -  Debenzylierung von Thionucleosiden mit Bortrichlorid (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 813-816 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methylthio-7-deazainosine and its α-Anomer  -  Debenzylation of Thionucleosides with Boron TrichlorideDebenzylation of the sugar moiety of pyrrolo[2,3-d]pyrimidine nucleosides without affecting methoxy or methylthio substituents of the chromophore has been accomplished by the action of boron trichloride/dichloromethane at  -  78°C. Applying this method to the protected derivatives 1b or 2b the methylthio nucleosides 3 and 4 were obtained in high yields.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820422
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Reaktionen mit Hexafluoracetonazin, XXI. [1,3-2,4]-Cycloaddition von elektronenarmen Mehrfachbindungs-Systemen an Hexafluoracetonazin  -  „Criss-cross“-Cycloaddition mit Acrylsäureestern (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 845-852 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Hexafluoroacetone Azine, XXI1).  -  [1,3-2,4] Cycloaddition of Electron-deficient Multiple Bond Systems to Hexafluoroacetone Azine  -  “Criss-cross” Cycloaddition Reactions with Acrylic Acid EstersHexafluoroacetone azine (1) and acrylic acid esters 2 react in a “criss-cross” cycloaddition process to give 1,5-diazabicyclo[3.3.0]octane dicarboxylates 3-5.
    Notes: Hexafluoracetonazin (1) reagiert mit Acrylsäureestern 2 (Molverhältnis 1:2) nach dem Schema der „Criss-cross“-Cydoaddition unter Bildung der 1,5-Diazabicyclo[3.3.0]octandicarbonsäureester 3-5.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Reaktionen mit Hexafluoracetonazin, XXII. Zum Reaktionsverhalten von Hexafluoracetonazin gegenüber Enolethern und Enaminen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 853-871 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Hexafluoroacetone Azine, XXII1).  -  Reaction Behaviour of Hexafluoroacetone Azine towards Enol Ethers and EnaminesHexafluoroacetone azine (1) reacts with enol ethers to give 1,3-cycloadducts. The azomethine imines 3 and 19a formed by reaction of 1 with vinyl ethers are capable to undergo a second cycloaddition step to give “criss-cross” cycloadducts (4, 5, 20). Contrary, the azomethine imines 14 and 19b derived from α-substituted enol ethers undergo heterolytic ring opening. The 1,x-dipoles formed spontaneously undergo a prototropic rearrangement to give hexafluoroacetone hydrazones (16, 17, 21).  -  In the reaction of 1 with enamines only for trans-N-(1-propenyl)piperidine a 1,3-cycloadduct can be detected spectroscopically at  -  15°C. Open chain as well as cyclic enamines having a β-hydrogen atom react to give hydrazones (25, 26, 28, 29). Enamines without hydrogen atoms in β-position and 1 in a [2 + 2] cycloaddition process yield azetidines 33.
    Notes: Hexafluoracetonazin (1) reagiert mit Enolethern unter 1,3-Cycloaddition. Die aus der Umsetzung von 1 mit Vinylethern und 2,3-Dihydrofuran hervorgehenden Azomethinimine 3 und 19a reagieren in einem zweiten Cycloadditionsschritt zu „Criss-cross“-Cycloaddukten (4, 5, 20). Dagegen unterliegen die von α-substituierten Enolethern und 2,3-Dihydro-4H-pyran abgeleiteten Azomethinimine 14, 19b einer heterolytischen Ringöffnung. Die entstehenden 1,x-Dipole wandeln sich spontan unter Protonenverschiebung in Hydrazone des Hexafluoracetons (16, 17, 21) um.  -  Bei der Reaktion von 1 mit Enaminen kann nur im Falle des trans-N-(1-Propenyl)piperidins ein 1,3-Cycloaddukt spektroskopisch bei  -  15°C nachgewiesen werden. Offenkettige wie auch cyclische Enamine mit β-ständigen Wasserstoffatomen liefern Hydrazone (25, 26, 28, 29). Enamine, die kein β-Wasserstoffatom besitzen, reagieren mit 1 nach dem Schema der [2 - 2]-Cycloaddition zu Azetidinen 33.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820505
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Phosphorpentoxid in der organischen Synthese, III. Neue Synthese von Pyrido[2,3-d]pyrimidin-4(3H)-onen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1012-1015 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phosphorus Pentoxide in Organic Synthesis, III1).  -  A New Synthesis of Pyrido[2,3-d]-pyrimidin-4(3H)-onesEthyl 2-acylamino-3-pyridinecarboxylates 1 were reacted with primary amine hydrochlorides, P2O5 and DMCA (N,N-dimethylcyclohexylamine) to yield a series of pyrido[2,3-d]pyrimidine-4(3H)-ones 2. The compounds 1 were prepared by acylating the corresponding ethyl 2-amino-3-pyridinecarboxylates. The new compounds were tested for pesticidal activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Ketenmercaptale mit kationischen Substituenten (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1022-1029 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ketene Mercaptals Bearing Cationic Substituents1,3-Dithiolylium bis(tetrafluoroborates) connected in position 2 to a methylene group which is bonded to a sulfonium, ammonium, amidinium, or (methylthio)methyleniminium substituent, are synthesized by various pathways. Their deprotonation affords the corresponding 1,2-dithiol-2-ylidenesulfonium, -ammonium. -amidinium. or -thioimidium acid ester tetrafluoroborates 4, 7, 11, 16, and 18. First links in this series are the ketene mercaptals 24 and 29 which are substituted by a sulfonium or amidinium group, and are accessible by other pathways.
    Notes: In 2-Stellung über eine Methylengruppe mit einem Sulfonium-, Ammonium-, Amidinium- oder (Methylthio)methyleniminiumsubstituenten verknüpfte 1,3-Dithiolylium-bis(tetrafluoroborate) werden auf verschiedenen Wegen synthetisiert und durch Deprotonierung in die entsprechend substituierten 1,3-Dithiol-2-ylidensulfonium-, -ammonium-, -amidinium- oder -thioimidium-säureester-tetrafluoroborate 4, 7, 11, 16 und 18 übergeführt. Anfangsglieder der Reihe sind die auf anderen Wegen zugänglichen, durch einen Sulfonium- oder Amidiniumrest substituierten Ketenmercaptale 24 und 29.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820603
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Darstellung ungesättigter Kohlenhydrate durch Esterpyrolyse, II. Thermische cis-Eliminierungen aus vollständig acetylierten Aldopyranosen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1039-1051 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Unsaturated Carbohydrates by Ester Pyrolysis, II1).  -  Thermal cis Eliminations from Completely Acetylated AldopyranosesThe pentaacetates 1, 2, 7, and 9 of β-D-glucose, α-D-mannose, β-D-allose, and β-D-galactose and the tetraacetates 13 and 18 of β-D-xylose and β-D-ribose eliminate when dissolved in acetone at temperatures about 350°C in a flow apparatus within 0.5-1 min regioselectively and stereo-selectively the 1-O-acetate group. The respective anomers with trans-bound hydrogen in position 2 do not give this reaction corresponding to the pericyclic elimination mechanism. In a subsequent [3,3] sigmatropic rearrangement the primarily formed 2,3,4,6-tetra-O-acetyl-1,5-anhydro-hex-1-enitols 3 (from 1 or 2), 8, and 10 as well as the 2,3,4-tri-O-acetyl-1,5-anhydropent-1-enitols 14 and 19 yield the α- or β-triacetyl-3-deoxy-hex-2-enopyranoses 4 or 5, 12 and the α- or β-triacetyl-3-deoxy-pent-2-enopyranoses 15 or 16, respectively. These products partially anomerize, e.g. 12 gives 11.  -  By further rearrangement with subsequent acetic acid anhydride elimination 5 and 16 are transformed into the enones 6 and 17.  -  1,2,4,6-Tetra-O-acetyl-3-deoxy-β-D-threo-hex-2-enopyranose (12) is described for the first time. The OH5(D) conformations of 11 and 12 are established by 13C NMR data.
    Notes: Die Pentaacetate 1, 2, 7 und 9 der β-D-Glucose, α-D-Mannose, β-D-Allose und β-D-Galactose sowie die Tetraacetate 13 und 18 der β-D-Xylose und β-D-Ribose, in Aceton gelöst, eliminieren in einer Strömungsapparatur bei Temperaturen um 350°C und Verweilzeiten von 0.5-1 min regioselektiv und stereoselektiv die 1-O-Acetylgruppe. Die jeweiligen Anomeren mit trans-ständigem Wasserstoff in 2-Position gehen entsprechend dem pericyclischem Eliminierungsmechanismus diese Reaktion nicht ein. Die primär gebildeten 2,3,4,6-Tetra-O-acetyl-1,5-anhydro-hex-1-enite 3, (aus 1 oder 2), 8 und 10 sowie die 2,3,4-Tri-O-acetyl-1,5-anhydro-pent-1-enite 14 und 19 führen nachfolgend in einer [3,3]-sigmatropen Umlagerung zu den α- oder β-Triacetyl-3-desoxy-hex-2-enopyranosen 4 oder 5, 12 bzw. den α- oder β-Triacetyl-3-desoxy-pent-2-enopyranosen 15 oder 16. Es erfolgt jeweils teilweise Anomerisierung, so von 12 zu 11.  -  Durch Umlagerung mit nachfolgender Essigsäureanhydrid-Eliminierung werden aus 5 und 16 die Enone 6 bzw. 17 gebildet.  -  Die 1,2,4,6-Tetra-O-acetyl-3-desoxy-β-D-threo-hex-2-enopyranose (12) wird erstmalig beschrieben. Die 13C-NMR-Daten beweisen, daß sowohl 11 als auch 12 bevorzugt in einer OH5(D)-Konformation vorliegen.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820605
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Darstellung ungesättigter Kohlenhydrate durch Esterpyrolyse, IV. Thermische cis-Eliminierungen aus vollständig acetylierten Aldo- und Ketofuranosen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1063-1067 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Unsaturated Carbohydrates by Ester Pyrolysis, IV1).  -  Thermal cis Eliminations from Completely Acetylated Aldo- and KetofuranosesThermal cis elimination of the anomeric acetyl group in completely acetylated furanoses does not yield the expected hydroxyglycals but gives by further elimination of another molecule of acetic acid substituted furans. Thus, β-D-ribofuranose tetraacetate 1 and β-D-galactofuranose pentaacetate 3 give the furans 2 or 4, respectively. α-D-Fructofuranose pentaacetate 5 equally yields the furan derivative 6. But in this case the E and Z isomers 7 and 8 with exocyclic double bond are also formed. Further rearrangement of these products is not observed.
    Notes: Die thermische cis-Eliminierung der anomeren Acetylgruppe in vollständig acetylierten Furanosen bleibt nicht auf der Stufe des Hydroxyglycals stehen, sondern führt unter Eliminierung eines weiteren Moleküls Essigsäure zu substituierten Furanen. So liefern β-D-Ribofuranosetetraacetat 1 und β-D-Galactofuranosepentaacetat 3 die Furane 2 bzw. 4. Auch α-D-Fructofuranosepentaacetat 5 ergibt den Furanabkömmling 6. Daneben werden jedoch die E- und Z-Isomeren 7 und 8 mit exocyclischer Doppelbindung gebildet. Weitere Umlagerung dieser Produkte wird nicht beobachtet.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820607
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Phosphor- und Schwefel-substituierte Allene in der Synthese, III. β-Ketosulfoxide aus 3-Alkin-1-olen über Allensulfoxide (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1096-1104 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus- and Sulfur-substituted Allenes in Synthesis, III1).  -  β-Keto Sulfoxides from 3-Alkyn-1-ols via Allenic SulfoxidesAllenic sulfoxides 3, readily available by [2,3] sigmatropic rearrangement of sulfenic esters 2 of 3-alkyn-1-ols 1, can be transformed to give β-keto sulfoxides 9 by nucleophilic addition of diethylamine and subsequent hydrolysis of the formed enamines.
    Notes: Aus Allensulfoxiden 3, die über die Sulfensäureester 2 von 3-Alkin-1-olen 1 durch eine [2,3]-sigmatrope Umlagerung leicht zugänglich sind, lassen sich durch Addition von Diethylamin und Verseifung der entstehenden Enamine β-Ketosulfoxide 9 gewinnen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Die Kristall- und Molekülstruktur des dimeren π-Allylpalladiumchlorid-Komplexes von Testosteron (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1111-1120 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal and Molecular Structure of the Dimeric π-Allyl-Palladium Chloride Complex of TestosteroneThe dimeric π-allyl-PdCl complex 2 of testosterone (1) crystallizes in the space group P21 with Z = 2, two water, and four 1,2-dichloroethane solvent molecules per unit cell. The crystal structure was determined by single-crystal X-ray analysis (R = 0.036 for 4533 reflections). Anomalous dispersion effects of the palladium atoms allowed the determination of the absolute configuration. The palladium atoms are coordinated on the α-face of the steroid molecules. The Pd2Cl2 bridges are folded by 135° between both PdCl coordination planes. The steroid skeletons in the complex are flatter than testosterone (1) itself and show significant conformational differences. 2 crystallizes in helices along the two-fold axis; the helices themselves are connected by hydrogen bonds and form sheets parallel with the (100) plane.
    Notes: Der dimere π-(4-6η)-PdCl-Komplex 2 von Testosteron (1) kristallisiert in der Raumgruppe P21 mit Z = 2, zwei Wasser- und vier 1,2-Dichlorethanlösungsmittelmolekülen pro Elementarzelle. Die Kristallstruktur wurde durch Einkristallröntgenstrukturanalyse (R = 0.036 mit 4533 Reflexen) bestimmt. Anomale Dispersionseffekte der Palladiumatome erlaubten die Bestimmung der absoluten Konfiguration. Die Palladiumatome stehen α-seitig. Die Pd2Cl2-Brücken bilden einen Faltungswinkel von 135° zwischen beiden PdCl-Koordinationsebenen. Die Steroidgerüste im Komplex sind flacher als im Testosteron (1) und zeigen signifikante Konformationsunterschiede. 2 kristallisiert in Helices entlang der Schraubenachse, wobei die Helices durch Wasserstoff-brücken verknüpft sind und Schichten parallel zu der (100)-Ebene bilden.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820612
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Bausteine von Oligosacchariden, XXXIX. Synthese der Glycopeptide β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Ser und β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Thr (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1121-1131 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building Units of Oligosaccharides, XXXIX1).  -  Synthesis of the Glycopeptides β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Ser and β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-ThrIn the presence of silver carbonate/silver perchlorate and dichloromethane/toluene as solvent 6-O-acetyl-2-azido-2-deoxy-3-O-trichloroacetyl-β-D-glucopyranosyl chloride (2) provides the α-glycosides 5 and 9 with derivatives of L-serine and L-threonine (3 and 7) with high stereoselectivity. Corresponding to this reaction the β-chloride of 2-azido-2-deoxylactose derivative 12 can be converted into disaccharide glycosides 13 and 14 with 3 or 7, respectively. Likewise, both reactions only yield α-glycosides stereoselectively. Removal of the protective groups from 13 and 14 results in the glycopeptides β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Ser (17) and β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Thr (20).
    Notes: 6-O-Acetyl-2-azido-4-O-benzyl-2-desoxy-3-O-trichloracetyl-β-D-glucopyranosylchlorid (2) läßt sich in Dichlormethan/Toluol bei Gegenwart von Silbercarbonat/Silberperchlorat mit dem Serin-derivat 3 und dem Threoninderivat 7 selektiv zu den α-Glycosiden 5 und 9 umsetzen. In einer entsprechenden Reaktion kann das β-Pyranosylchlorid des 2-Azido-2-desoxylactose-Derivates 12 mit 3 und 7 zu den Disaccharid-Glycosiden 13 und 14 umgesetzt werden. Beide Reaktionen lassen sich ebenfalls stereoselektiv nur zum α-Glycosid lenken. Durch vollständige Entblockierung von 13 und 14 sind die beiden Glycopeptide β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Ser (17) und β-D-Gal(1 → 4)-α-D-GlcNAc(1 → O)-L-Thr (20) zu erhalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820613
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Synthesen, spektroskopische Untersuchungen und Prüfung auf antibakterielle Wirksamkeit von einigen Pfeffer-Alkaloiden. Olefinierungsreaktionen mit Phosphorylacetamiden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1142-1149 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Spectroscopic Examination, and Testing for Antibacterial Activity of Some Pepper Alkaloids. Olefination Reactions with Phosphorylacetamides4,5-Dihydrowisanine (4) and 4,5-dihydrookolasine (3) as well as 1-(2-methoxy-4,5-methylene-dioxycinnamoyl)piperidine (5) are three alkaloids which have been isolated from Piper guineense and Piper peepuloides, respectively. They have been synthesized by Horner-Wittig reaction of 3-(2-methoxy-4,5-methylenedioxyphenyl)propionaldehyde (11) and 2-methoxy-4,5-methylene-dioxybenzaldehyde (8) with 1-(diethoxyphosphorylacetyl)piperidine (6) and -pyrrolidine (7), respectively. The Horner-Wittig reaction gave products having E-configuration. The amides are not or only slightly active against bacteria.
    Notes: 4,5-Dihydrowisanin (4) und 4,5-Dihydrookolasin (3) sowie 2-Methoxy-4,5-methylendioxyzimtsäure-piperidid (5) sind drei aus Piper guineense bzw. Piper peepuloides isolierte Alkaloide. Sie wurden durch Horner-Wittig-Reaktion von 3-(2-Methoxy-4,5-methylendioxyphenyl)propionaldehyd (11) bzw. 2-Methoxy-4,5-methylendioxybenzaldehyd (8) mit 1-(Diethoxyphosphoryl-acetyl)piperidin (7) bzw. -pyrrolidin (6) hergestellt. Die Horner-Wittig-Reaktion ergab Verbindungen mit E-Konfiguration. Die Amide sind nicht oder nur schwach antibakteriell wirksam.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820615
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Stereocontrolled Synthesis of the Insect Growth Regulators  -  Alkyl (2E,4E)-Dodecadienoates (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1173-1182 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselektive Synthese von (2E,4E)-Dodecadiensäureestern als InsektenwachstumsregulatorenDie Titelverbindungen 1 und 16 wurden durch Kondensation der Dianionen von β-Dicarbonylverbindungen 5 und 11 mit Aldehyden 4 und Addition von Alkyllithium/Kupfer(I)-iodid an Enolacetate oder Enolphosphate der ungesättigten β-Dicarbonylverbindungen 8 und 15 stereoselektiv synthetisiert.
    Notes: The title compounds 1 and 16 were synthesized by condensation of the dianions of β-keto esters 5 and 11 with aldehydes 4, and lithium dialkylcuprate addition to the enol acetate or enol phosphate of unsaturated β-keto esters 8 and 15. The (2E,4E)-dodecadienoate derivatives 1 and 16 were formed in a stereoselective manner.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820618
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Pyridylsubstituierte Cyclobutane durch Photodimerisierung von Azastilbenen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1183-1210 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyridyl-substituted Cyclobutanes via Photodimerisation of AzastilbenesMono- and diazastilbenes A1-A9 as well as their mono- and dihydro- or -alkyl quaternary salts are irradiated (UV). Mono salts are smoothly converted into cyclobutanes C in crystalline state and/or in solution. The free bases A or their bis salts, reacting in solution only, form partly or exclusively different products. Their structures together with the constitutions and configurations of the cyclobutanes A are elucidated. Results from the literature are partly confirmed and partly corrected.
    Notes: Die Mono- und Diazastilbene A1-A9 werden, auch als ihre Mono- und Dihydro- oder -alkyl-Quartärsalze, mit UV-Licht bestrahlt. Die Monosalze werden im Kristall und/oder in Lösung glatt zu Cyclobutanen C dimerisiert. Die freien Basen A oder ihre Bis-Salze, die nur in Lösung reagieren, bilden teilweise oder vollständig andere Produkte. Deren Struktur, sowie die Konstitution und Konfiguration von C1-C9 werden aufgeklärt. Literaturergebnisse werden teils bestätigt, teils korrigiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820619
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Notizen. Synthese von (2E,4Z)-2,4,11-Dodecatrien-1-al, einem Abbauprodukt der Linolensäure (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1216-1219 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of (2E,4Z)-2,4,11-Dodecatrien-1-al, a Degradation Product of Linolenic Acid(2E,4Z)-2,4,11-Dodecatrien-1-al (13) has been prepared by using β-bromoallyl alcohol (9) and 1,8-nonadiyne (10) as starting materials. 13 is in agreement with all properties of the natural compound. The synthesis via a Wittig reaction, however, leads to a partial isomerisation of the terminal double bond.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Alkaloide in Tabernaemontana-Arten, XIV. Zur massenspektroskopischen Fragmentierung des Vincadiffins (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1223-1227 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkaloids in Tabernaemontana Species, XIV1).  -  The Mass Spectrometric Fragmentation of VincadiffineThe mass spectrum of the 2-acylindole alkaloid vincadiffine (2) is characterized by intensive ions at m/e = 178 and m/e = 180 and the fragmentation sequence . These observations are not in agreement with earlier reports and therefore were the object of special investigations.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820623
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Preparation and some reactions of bis(thioacyl) sulfides (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1229-1244 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und einige Reaktionen von Bis(thioacyl)sulfidenDurch Umsetzung von Dithiocarbonsäuren mit Dicyclohexylcarbodiimid wurden die Bis-(thioacyl)sulfide 1, die nützliche und unter milden Reaktionsbedingungen einsetzbare Thioacylierungsmittel sind, dargestellt. Die aliphatischen Thioanhydride (1, R = Aliphaten) sind thermisch labile und feuchtigkeitsempfindliche purpurne öle, die bei Raumtemperatur zu den Dithietanen 5 dimerisieren, während die meisten aromatischen Derivate (1, R = Aromaten) tiefgrüne, einigermaßen stabile Kristalle bilden. Einige Reaktionen mit Nucleophilen werden diskutiert.
    Notes: Reaction of dithioic acids with dicyclohexylcarbodiimide has been found to give the corresponding bis(thioacyl) sulfides 1 in good yield, which are very useful thioacylating reagents under mild reaction conditions. Most of the aromatic thioanhydrides (1, R = aromatic) are fairly stable green crystals at room temperature, but the aliphatic ones (1, R = aliphatic) are unstable purple oils which dimerize at room temperature to give the dithietanes 5. The reactions with nucleophiles are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820702
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Tetrapyrrol-Biosynthese, 13. Synthese linearer Di-, Tri-, Tetra- und Pentapyrrole mit natürlichen Seitenketten und günstigen Eigenschaften (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1261-1271 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetrapyrrole Biosynthesis, 131).  -  Synthesis of Linear Di-, Tri-, Tetra-, and Pentapyrroles with Natural Side Chains and Favourable PropertiesBy application of a substantially simplifying synthetic conception which avoids the conventional use of ester protective groups, the even-numbered (12, 15) and odd-numbered oligopyrrols (17, 19) were prepared from the monopyrrole 4. These oligopyrroles owe favourable condensation and solubility properties to their propionic acid side chains  -  which are also present in natural products containing pyrrole  -  and are useful model compounds.
    Notes: Mit Hilfe eines stark vereinfachten Synthesekonzepts, das die konventionelle Anwendung von Esterschutzgruppen vermeidet, wurden die geradzahligen (12, 15) und ungeradzahligen Oligopyrrole (17, 19) aus dem Monopyrrol 4 erstmalig dargestellt. Diese Oligopyrrole verdanken ihren  -  auch in Pyrrol-Naturstoffen enthaltenen  -  Propionsäureseitenketten günstige Kondensations-und Löslichkeitseigenschaften und stellen nützliche Modellverbindungen dar.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820704
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Polycyclische Verbindungen, XXII. Versuche zum Aufbau des Aporphingerüstes aus Dehydroaromaten (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1297-1303 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, XXII1).  -  Experiments Towards the Synthesis of the Aporphine Skeleton from ArynesThe heterocycles 5 and 6 with the ring skeleton of the aporphine alkaloids are obtained from the epoxyhexahydrophenanthrene 1. Key steps of this synthesis are the introduction of the nitrogen atom by means of potassium thiocyanate and a directed aldol reaction.
    Notes: Die Heterocyclen 5 und 6 mit dem Ringgerüst der Aporphin-Alkaloide werden ausgehend von dem Epoxyhexahydrophenanthren 1 hergestellt. Schlüsselreaktionen der Synthese sind die Einführung des Stickstoffs mit Hilfe von Kaliumthiocyanat und eine gezielte Aldolreaktion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820707
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Pilzpigmente, 40. Leprocybin, der Fluoreszenzstoff von Cortinarius cotoneus und verwandten Leprocyben (Agaricales) (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1280-1296 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fungus Pigments, 401).  -  Leprocybin, the Fluorescent Principle of Cortinarius cotoneus and Related Leprocybes (Agaricales)Leprocybin (1), a glucoside responsible for the yellow-green fluorescence of the fruiting bodies under UV light has been isolated from Cortinarius toadstools (subgenus Leprocybe, section Leprocybe Mos.). On acid hydrolysis or action of β-glucosidase 1 was split into its aglycone leprocyboside (6), the constitution of which was elucidated by several derivatisations, decarboxylation to 10, and alkaline degradation. Final structural proof of the pyranoxanthone system was obtained by synthesis of 8-O-methyl(decarboxy)leprocyboside (12).
    Notes: Aus Pilzen der Gattung Cortinarius (Untergattung Leprocybe, Sektion Leprocybe Mos.) wurde das Glucosid Leprocybin (1) isoliert, das für die gelbgrüne Fluoreszenz der Fruchtkörper im UV-Licht verantwortlich ist. 1 ließ sich durch saure Hydrolyse oder β-Glucosidase in das Aglycon Le-procybosid (6) spalten, dessen Konstitution durch verschiedene Derivatisierungen, Decarboxylierung zu 10 und Alkaliabbau ermittelt wurde. Der endgültige Strukturbeweis für das Pyrano-xanthon-System erfolgte durch Synthese von 8-O-Methyl(decarboxy)leprocybosid (12).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820706
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Aminoethinylierungen, 31) Notiz über die Synthese von [(Dialkylamino)ethinyl]ketonen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 196-199 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aminoethynylation, 31) - Note on the Synthesis of [(Dialkylamino)ethynyl]ketonesUnder controlled conditions N,N-dialkyl[(trimethylstannyl)ethynyl]amines 1 react with acid chlorides to yield the title compounds 2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Umsetzungen N-Acyl-substituierter α-Chlorformamidine mit nucleophilen ReagenzienHerrn Prof. Dr. L. Horner zum 70. Geburtstag gewidmet. (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 201-210 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of N-Acyl Substituted α-Chloroformamidines with Nucleophilic ReagentsThe N-acyl substituted chloroformamidines 1a and b are hydrolyzed to the ureas 2a and b. Reaction of 1a with C-, S-, and N-nucleophilic reagents leads to the products 3, 4a, b, 5a-c, 6a-f, 7a-h, and 8a-d. Compound 1a reacts with potassium thiocyanate and potassium selenocyanate to form the substituted 1,3,5-oxadiazines 9a and b, while the reaction with sodium azide produces the tetrazole 10. The guanidine 7a can be converted into the acylated compounds 11a and b.
    Notes: Die N-Acyl-substituierten α-Chlorformamidine 1a und b hydrolysieren zu den Harnstoffderivaten 2a bzw. b. Die Umsetzung von 1a mit C-, S- und N-nucleophilen Reagenzien liefert die Substitutionsprodukte 3, 4a, b, 5a-c, 6a-f, 7a-h und 8a-d. Mit Kaliumthiocyanat und Kalium-selenocyanat bildet 1a die substituierten 1,3,5-Oxadiazine 9a und b, mil Natriumazid das Tetrazolderivat 10. Das Guanidin 7a kann in die acylierten Verbindungen 11a und b übergeführt werden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Zur cyclisierenden Carbonylierung von 3-Hydroxycarbohydroxamsäuren mit 1,1′-Carbonyldiimidazol1a) (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 219-225 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Carbonylation of 3-Hydroxycarbohydroxamic Acids with 1,1′-CarbonyldiimidazoleThe reaction of 3-hydroxycarbohydroxamic acids 3 with 1,1′-carbonyldiimidazole produces as a function of the substitution of 3 heterocycles of type 1, 4, and 5. In the presence of imidazole the 3-(2-hydroxyalkyl)-1,4,2-dioxazol-5-ones 1 undergo rearrangement into 2-oxazolidones 2.
    Notes: 3-Hydroxycarbohydroxamsäuren 3 reagieren mit 1,1′-Carbonyldiimidazol in Abhängigkeit von der Substitution des Säurerestes zu den Heterocyclen vom Typ 1, 4 und 5. Aus den 3-(2-Hydroxyalkyl)-1,4,2-dioxazol-5-onen 1 erhält man durch Imidazolkatalyse 2-Oxazolidone 2.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    (2-Chloralkyliden)amin-oxide als Alkylierungsmittel; Reaktionen mit Aminen und den Anionen von Malonsäure-dialkylestern (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 226-230 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (2-Chloralkylidene)amine Oxides as Alkylation Reagents; Reactions with Amines and the Anions of Dialkyl MalonatesAminolysis of N-(2-chloroethylidene)cyclohexylamine oxide (1) in ether at 25°C with the amines 2a-d yields the (2-aminoalkylidene)amine oxides 3a-d. The aminolysis of 1 with the tertiary amines 5a-c yields the ammonium salts 6a-c, and the reaction of N-(2-chloropropylidene)-cyclohexylamine oxide (8) in benzene at 60°C with the anions of dialkyl malonates (7a, b) yields the nitrones 9a, b. The hydrolytic cleavage of 9a, b to the aldehydes 10a, b is described.
    Notes: Aminolyse von N-(2-Chlorethyliden)cyclohexylamin-oxid (1) in Ether bei 25°C mit den Aminen 2a-d liefert die (2-Aminoalkyliden)amin-oxide 3a-d. Durch Aminolyse von 1 mil den tertiären Aminen 5a-c entstehen die Ammoniumsalze 6a-c, und durch Reaktion von N-(2-Chlorpropyliden)cyclohexylamin-oxid (8) in Benzol bei 60°C mit den Anionen der Malonsäure-dialkylester (7a, b) werden die Nitrone 9a, b erhalten. Die hydrolytische Spaltung von 9a, b zu den Aldehyden 10a, b wird beschrieben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Synthese der enantiomeren Melochinine (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1466-1477 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the Enantiomeric MelochininesBoth enantiomers of the pyridone alkaloid melochinine (1) have been synthesized in the following way: The dienolate dianion 3a, formed exclusively from 3-hydroxy-2,6-dimethyl-4-pyrone (3) and lithium bis(trimethylsilyl)amide at - 70°C, reacts with 10-(tetrahydro-2-pyranyloxy)-1-undecanal (6) to give 7, then 8 by methylation, 9 by elimination of water, and finally the pyrone 10 by catalytic hydrogenation in 48% overall yield. Reaction of 10 with ammonia/methanol produces rac-1. Natural (-)-(R)-melochinine (1) and its artificial enantiomer are produced by using the aldehydes (R)-6 and (S)-6 in the synthesis described above. The enantiomeric aldehydes (R)-6 and (S)-6 are prepared in three steps from (+)-(R)- and (-)-(S)-1,2-epoxypropane, respectively. The starting material 3 ist produced from 1-(5-methyl-2-furyl)ethanol (2) by treatment with chlorine/water.
    Notes: Beide Enantiomeren des Pyridonalkaloids Melochinin (1) werden auf folgende Weise synthetisiert: Bei der Deprotonierung von 3-Hydroxy-2,6-dimethyl-4-pyron (3) mit Lithium-bis(trimethylsilyl)amid bei - 70°C entsteht ausschließlich das Dienolat-Dianion 3a. Es reagiert bei dieser Temperatur mit 10-(Tetrahydro-2-pyranyloxy)-1-undecanal (6) zur Verbindung 7, welche durch Methylieren, Eliminieren von Wasser und katalytisches Hydrieren über 8 und 9 mit 48% Gesamtausbeute in das Pyron 10 übergeführt wird. Einwirkung von Ammoniak/Methanol auf 10 ergibt rac-1. Das natürliche (-)-(R)-Melochinin (1) und sein in der Natur nicht vorkommendes Enantiomeres werden erhalten, wenn man in der Synthese die Aldehyde (R)-6 und (S)-6 einsetzt. Die enantiomeren Aldehyde 6 werden in drei Stufen aus (+)-(R)- bzw. (-)-(S)-1,2-Epoxypropan erhalten. Das Ausgangsmaterial 3 entsteht aus 1-(5-Methyl-2-furyl)ethanol (2) durch Reaktion mit Chlor/Wasser.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820806
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Trimethoxyphenylverbindungen, IX. Borheterocyclen in der präparativen Naturstoffchemie: Eine einfache Synthese des Aurentiacins (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1509-1513 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethoxyphenyl Compounds, IX.  -  Boron Heterocycles in Preparative Natural Products Chemistry: A Simple Synthesis of Aurentiacin2,4,6-Trimethoxytoluene, C6H5-X-CO2H (X = CH=CH, CH2-CH2), and boron trifluoride reacted, by selective demethylation, to give crystalline boron heterocycles and, by subsequent hydrolysis, aurentiacin (3b) and dihydroaurentiacin (3c). 2-Phenylpropionic acid acylated 4-hydroxy-2,6-dimethoxytoluene without demethylation. Under more vigorous conditions, diacylation occurred which was accompanied by demethylation. The second acyl group was easily lost.
    Notes: 2,4,6-Trimethoxytoluol ergab mit C6H5-X-CO2H (X = CH = CH, CH2-CH2) und Bortrifluorid unter selektiver Entmethylierung kristalline Borheterocyclen. Deren Hydrolyse lieferte Aurentiacin (3b) und Dihydroaurentiacin (3c). 4-Hydroxy-2,6-dimethoxytoluol nahm einen (2-Phenylpropionyl)-Rest ohne, unter verschärften Bedingungen einen zweiten mit gleichzeitiger Entmethylierung auf. Der zweite Acylrest wurde leicht wieder abgespalten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820810
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Aufbau des Insulinsegments B 13-20 nach der Liquid-Phase-Methode und Synthesekontrolle der trägergebundenen Peptide durch 13C-NMR-Spektroskopie (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1514-1531 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the Insulin Segment B 13-20 with the Liquid-Phase Method and Control of the Synthesis by 13C NMR Spectroscopy of the Support-bound PeptidesThe protected partial sequence B 13-20 of the insulin B chain has been synthesized stepwise according to the liquid-phase method: Boc-Glu(Bzl)-Ala-Leu-Tyr(Bzl)-Leu-Val-Cys(Bzl)-Gly-OPOE (8) [POE = polyoxyethylene]. The partially protected octapeptide Boc-Glu-Ala-Leu-Tyr(Bzl)-Leu-Val-Cys(Bzl)-Gly-OH (9) was split off from the solubilizing polymeric support by alkaline saponification. Each synthetic step was controlled by 13C NMR spectroscopy of the polyoxyethylene-bound peptides 1-8. The 13C NMR spectra (20.63 MHz) of all polymer-bound intermediates 1-8 and of the cleaved octapeptide 9 were in agreement with the expected signal positions of the amino acid residues. However, the 100.62-MHz 13C NMR spectrum of the polymer-bound octapeptide 8 revealed a benzyl rearrangement at the tyrosine ring. Beginning with the hexapeptide 6 the onset of an α-helical secondary structure was found by circular dichroism measurements. This conformation also reflects in the 13C NMR spectra by typical shifts of the CO, Cα and side-chain signals.
    Notes: Die geschützte Partialsequenz B 13-20 der Insulin-B-Kette wurde schrittweise mit Hilfe der Liquid-Phase-Methode aufgebaut: Boc-Glu(Bzl)-Ala-Leu-Tyr(Bzl)-Leu-Val-Cys(Bzl)-Gly-OPOE (8) [POE = Polyoxyethylen]. Das partiell geschützte Octapeptid Boc-Glu-Ala-Leu-Tyr(Bzl)-Leu-Val-Cys(Bzl)-Gly-OH (9) wurde durch alkalische Verseifung vom solubilisierenden Polymerträger abgespalten. Jede Synthesestufe wurde durch 13C-NMR-Spektroskopie der polyoxyethylengebundenen Peptide 1-8 kontrolliert. Die 13C-NMR-Spektren (20.63 MHz) aller polymergebundenen Zwischenprodukte 1-8 und vom abgespaltenen Octapeptid 9 zeigten übereinstimmung mit den erwarteten Signallagen der Aminosäurebausteine. Im 100.62-MHz-13C-NMR-Spektrum des polymergebundenen Octapeptids 8 wurde jedoch eine Benzylumlagerung am Tyrosinring entdeckt. Ab dem Hexapeptid 6 ergeben sich anhand von Circulardichroismus-Messungen eindeutige Hinweise auf die Ausbildung einer α-helikalen Sekundärstruktur. Diese Konformation spiegelt sich auch in den 13C-NMR-Spektren durch typische Verschiebungen der CO-, Cα- und Seitenketten-Signale wider.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820811
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Pheromone, 7. Kolbe-Synthese von 29-tert-Butyldimethylsilyloxy-3,11-dimethyl-1-nonacosen, einer Schlüsselverbindung zur Darstellung eines optisch aktiven Sexuallockstoffes der Deutschen Hausschabe (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1532-1542 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pheromones, 7.  -  Kolbe Synthesis of 29-tert-Butyldimethylsilyloxy-3,11-dimethyl-1-nonacosene, a Key Intermediate for the Preparation of an Optically Active Pheromone of the German Cockroach29-tert-butyldimethylsilyloxy-3,11-dimethyl-1-nonacosene (17) is synthesized by Grignard coupling of p-tolyl (S)-24-tert-butyldimethylsilyloxy-6-methyl-1-tetracosanesulfonate (15) with 5-bromo-3-methyl-1-pentene (16). The tosylate is prepared from methyl (S)-24-hydroxy-6-methyltetracosanate (11) by protection of the free hydroxyl group and reduction of the ester function. The ester 11 is obtained by twofold Kolbe electrolysis of 18-hydroxyoctadecanoic acid (5) with methyl (S)-3-methylglutarate (6) and with methyl glutarate (9). The bromide 16 is also sythesized from the half-ester 6 by reduction of the ester function and elimination of phenyl selenide.
    Notes: 29-tert-Butyldimethylsilyloxy-3,11-dimethyl-1-nonacosen (17) wird durch Grignardkupplung von p-Tolyl-(S)-24-tert-butyldimethylsilyloxy-6-methyl-1-tetracosansulfonat (15) mit 5-Brom-3-methyl-1-penten (16) synthetisiert. Das Tosylat 15 ist aus (S)-24-Hydroxy-6-methyltetracosansäure-methylester (11) durch Schutz der freien Hydroxylgruppe und Reduktion der Esterfunktion mit anschließender Tosylierung erhältlich. Der Ester 11 wird durch doppelte Kolbe-Elektrolyse von 18-Hydroxyoctadecansäure (5) mit (S)-3-Methylglutarsäure-monomethylester (6) und an-schließend mit Glutarsäure-monomethylester (9) aufgebaut. Das Bromid 16 wird ebenfalls aus dem Halbester 6 durch Reduktion der Esterfunktion und Phenylselenid-Eliminierung synthetisiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820812
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Notizen Brückenkopfazide, 4. Notiz zur Herstellung von Brückenkopfaminen durch Reduktion von Brückenkopfaziden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1566-1568 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bridgehead Azides, 4.  -  Note on the Preparation of Bridgehead Amines by Reduction of Bridgehead AzidesCatalytic hydrogenation of readily available bridgehead azides gives high yields of the corresponding bridgehead amines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    A Convenient Synthesis of 1- and 3-Acetylphenothiazines (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1573-1574 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eine einfache Synthese von 1- und 3-Acetylphenothiazinen1-Acetylphenothiazin (2) und 3-Acetylphenothiazin (3) können photochemisch aus 10-Acetyl-phenothiazin (1) hergestellt werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820818
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Darstellung und Reaktionen von 2-(Dialkylamino)malonaldehyden (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 530-535 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of 2-(Dialkylamino)malonaldehydes1,2)Vilsmeier formylation of enediamines 1 leads to 2-(dialkylamino)malonaldehydes 5. These substituted malonaldehydes and their derivatives 3 and 4 are valuable starting materials for the synthesis of dialkylamino-substituted pentamethine cyanine dyes 7 as well as five- and six-membered heterocycles such as 8 and 9.
    Notes: Vilsmeier-Formylierung der En-Diamine 1 führt zu den 2-(Dialkylamino)malonaldehyden 5. Diese substituierten Malonaldehyde und ihre Derivate 3 und 4 sind wertvolle Ausgangsverbindungen für die Synthese dialkylaminosubstituierter Pentamethincyanine 7 sowie 5- und 6gliedriger Hetero-cyclen 8 und 9.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Pheromone, XXXV. Stereoselektive Synthesen von 1,4-Alkadienen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 536-544 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pheromones, XXXV1). - Stereoselective Syntheses of 1,4-Alkadienes2)The stereoselective synthesis of 1,4-alkadienes via Julia synthesis, Wittig reaction, Crombie synthesis and methylene interruption of conjugated alkadienylphosphonates is described.
    Notes: Es wird die stereoselektive Synthese von 1,4-Alkadienen mittels Julia-Synthese, Wittig-Reaktion, Crombie-Synthese und Methylenunterbrechung konjugierter Alkadienylphosphonate beschrie-ben.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Chromatographic Separation and Spectroscopic Characterization of the Bilirubin Isomers IIIα, IXα, XIIIα and Their Dimethyl Esters (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1759-1765 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chromatographische Trennung und spektroskopische Charakterisierung der Bilirubin-Isomeren IIIα, IXα und XIIIα sowie ihrer DimethylesterDie drei Strukturisomeren Bilirubin IXα (1a), IIIα (2a) und XIIIα (3a) wurden im präparativen Maßstab mittels hochauflösender Niederdruckflüssigkeitschromatographie getrennt. Außer UV-, IR- und MS-Daten von 1a, 2a und 3a und ihren Dimethylestern 1b, 2b und 3b werden auch vollständig zugeordnete 1H-NMR-Daten angegeben, die allein eine quantitative spektroskopische Analyse von Mischungen der isomeren Dimethylester ermöglichen.
    Notes: The three structural isomers bilirubin IXα (1a), IIIα (2a), and XIIIα (3a) have been separated on a preparative scale by high-performance low-pressure liquid chromatography. They were converted into their dimethyl esters 1b, 2b, and 3b and characterized by UV, IR, MS, and fully assigned 1H NMR data. NMR is the only spectroscopic method which makes it possible to analyze mixtures of the three isomeric dimethyl esters quantitatively.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821002
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Nucleoside, XXXVIII. Synthese und Eigenschaften von 1-(β-D-Ribofuranosyl)-2-chinoxalinonen und -2,3-chinoxalindionen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 754-761 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, XXXVIII1).  -  Synthesis and Properties of 1-(β-D-Ribofuranosyl)-2-quinoxalinones and -2,3-quinoxalinedionesThe 2-quinoxalinones 4-6 and 2,3-quinoxalinediones 16-18 have been ribosylated via the silyl method under Et2O-BF3 catalysis leading to the corresponding nucleosides 10-12 and 22-24, respectively, Removal of the blocking groups led to the free quinoaxalinenucleosides 13-15 and 25-27 in good yields. The newly synthesized compounds were characterized by UV and NMR spectra.
    Notes: Die 2-Chinoxalinone 4-6 und 2,3-Chinoxalindione 16-18 warden nach der Silyl-Methode unter Et2O-BF3-Katalyse ribosidiert und liefern hierbei die entsprechenden Nucleoside 10-12 bzw. 22-24. Durch Schutzgruppenabspaltung lassen sich hieraus die freien Chinoxalinnucleoside, 13-15 bzw. 25-27 in guten Ausbeuten isolieren. Die neu dargestellten Verbindungen werden durch UV- und NMR-Spektren charakterisiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820417
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Pteridine, LXXI. Synthese und photochemisches Verhalten von 8-substituierten Lumazinen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 762-779 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pteridines, LXXI1).  -  Synthesis and Photochemical Behaviour of 8-Substituted LumazinesThe 8-substituted lumazines 34-69 have been synthesized from 6-chloro-5-nitrouracil (1) and its 3-methyl derivative 2 via the corresponding 6-amino-5-nitrouracils 3-26, substituted at the amino nitrogen. The photochemical properties of the 8-substituted lumazines have been investigated. Various photoreactions were observed depending on the chemical nature of the N-8 side-chain and leading to an easy photodealkylation of the β-hydroxy-, β-methoxy-, and β-aminoethyl derivatives 34-44. Increasing donor properties of the β-substituent enhances the photolabilty which is expressed in a Norrish-type II cleavage reaction to the corresponding lumazines 70-75. 8-Cycloalkyllumazines 52-54 show photoreduction to 7,8-dihydrolumazines 76-78. The newly synthesized 8-substituted lumazine derivatives have been characterized by elementary analyses and UV spectra. Structural peculiarities due to the various substituents in position 6, 7, and 8 will be discussed.
    Notes: Ausgehend von 6-Chlor-5-nitrouracil (1) und seinem 3-Methyl-Derivat 2 warden über die entsprechenden am Aminostickstoff substituierten 6-Amino-5-nitrouracile 3-26 die 8-substituierten Lumazine 34-69 dargestellt. Ihr photochemisches Verhalten wird untersucht. In Abhängigkeit von der chemischen Natur der N-8-Seitenkette laufen unterschiedliche Photoreaktionen ab von denen vor allem die leichte Photodealkylierung der β-Hydroxy-, β-Methoxy- und β-Aminoethyl-Derivate 34-44 herausragt. Mit zunehmender Donatoreigenschaft des β-Substituenten steigt auch die Photolabilität, die sich in einer Norrish-Typ-II-Spaltung zu den entsprechenden Lumazinen 70-75 kundtut. Die 8-Cycloalkyllumazine 52-54 erleiden eine Photoreduktion zu den 7,8-Dihydrolumazinen 76-78. Sämtliche neuen 8-substituierten Lumazine werden durch Analysen und UV-Spektren charakterisiert und strukturelle Besonderheiten, bedingt durch die verschiedenen Substituenten in 6-, 7- und 8-Stellung, diskutiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Masthead (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982) 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219820501
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Synthetische Anthracyclinone, XXI. Synthese des 3-Desmethoxyaranciamycinons (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1907-1919 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthetic Anthracyclinones, XXI1).  -  Synthesis of 3-DemethoxyaranciamycinoneThe intramolecular Wittig reaction of the ylide 8b leads to the dihydronaphthacene 9b which can be transformed into the ketol 16 by cis-hydroxylation and pyridinium chlorochromate oxidation. A hydroxy group at C-4 can be introduced either by bromination followed by treatment with diluted alkali or by direct base catalysed hydroxylation leading to the 2,4-cis-diol 18 with high stereoselectivity. The reaction of the bromination products 17a/17b with silver trifluoromethane-sulfonate predominately yields the epimeric 2,4-trans-diol 19 (3-demethoxyaranciamycinone) besides minor amounts of 18 and the elimination product 20.
    Notes: Die intramolekulare Wittig-Reaktion des Ylids 8b führt zum Dihydronaphthacen 9b, das durch cis-Hydroxylierung und Pyridiniumchlorochromat-Oxidation zum Ketol 16 umgewandelt werden kann. Eine Hydroxygruppe an C-4 kann entweder durch Bromierung  -  gefolgt von Behandlung mit verdünntem Alkali  -  oder durch direkte basenkatalysierte Hydroxylierung eingeführt werden und liefert mit hoher Stereoselektivität das 2,4-cis-Diol 18. Die Reaktion der Bromierungsprodukte 17a/17b mit Silber-trifluormethansulfonat ergibt hauptsächlich das epimere 2,4-trans-Diol 19 (3-Desmethoxyaranciamycinon) neben geringeren Mengen 18 und dem Eliminierungsprodukt 20.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821012
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Baeyer-Villiger-Reaktion an 1-Acetyl-1,3,5-cycloheptatrienen (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1924-1926 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Baeyer-Villiger Reaction with 1-Acetyl-1,3,5-cycloheptatrienesIn order to synthesize a homologue of acetylsalicylic acid the Baeyer-Villiger reaction of 1-acetyl-1,3,5-cycloheptatrienes 1a-c has been tested. The corresponding acetoxycycloheptatrienes 2a-c were obtained in good yields (51-71 percent).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821014
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    A Method for the Simultaneous Preparation of Alkyl Isothiocyanates and Thiols (1982)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1927-1932 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ein Verfahren für die gleichzeitige Gewinnung von Alkylisothiocyanaten und ThiolenAus primären Alkylaminen wurden Ethyl-, Butyl-, Isobutyl- und n-Dodecyldithiocarbamate 2 hergestellt. Letztere lassen sich leicht zu den Isothiocyanaten 3 und Thiolen 4 pyrolysieren. Die Massenspektren der Ester sowie deren Pyrolyseprodukte wurden gemessen.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198219821015
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...