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  • Organic Chemistry  (1,315)
  • 1980-1984  (1,315)
  • 1984  (646)
  • 1980  (669)
  • 1
    Electronic Resource
    Electronic Resource
    Synthetic routes to trace constituents of algal pheromone bouqets and other information-imitating substances (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 616-624 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Structural modifications of multifidene (1), viridiene (2) and ectocarpene (5) led to the synthesis of eleven new pheromone components or imitatin substances mostly by Grignard alkylation of cyclopentene and cycloheptadiene synthons. A new lactone α,ω dienol conversion is reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670230
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  • 2
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    Electronic Resource
    Photoelectron-Spectroscopic Characterization of 3,4-Dimethyl-2,4-hexadienes (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 640-653 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The He(Ia) photoelectron (PE) spectra of the (E,E)-, (E,Z)- and (Z,Z)-isomers of the title compound have been recorded to obtain information about their conformation in the gas phase. For a valid correlation with the PE data of other dienes it is necessary to take the potentials V(ϕ) for internal rotation and the corresponding conformer population densities P (ϕ) into account, as well as the rather complicated way wy in which the π-1 ionization energy gap ΔI(ϕ) depends on the direct π-orbital interaction and the long-range ‘through-space’ interaction between the semi-localized methyl-group orbitals and the π-orbitals. These factors being taken into account, the mean twist angles, ϕ, compatible with the PE-spectroscopic results are ϕ (E,E) ≍ O° ± 30°, ϕ (E,Z) ≍ 80° or 110° within ± 15°, and ϕ (Z,Z) ≍ 85° to 105°. These results are in rough agreement with electron diffraction data by Traetteberg [15], other spectroscopic results and, for the (E, E)- and (Z,Z)-isomers, internal rotation potentials V(ϕ) previously calculated by Roth [17]. On the other hand the potential V (ϕ) proposed for the (E,Z)-isomer does not seem to be compatible with our findings.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670303
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  • 3
    Electronic Resource
    Electronic Resource
    Cob(I)alamin Differentiating Alkenes During Saturation11th Communication in the series ‘Cob(I)alamin as Catalyst’; for the 10th communication see [1a]. (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 669-683 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The olefins 2, 7, 11, and 19, have been reduced using catalytic amounts of cob(I)alamin(I(I)). During a slow saturation, the catalyst is able to differentiate the two diastereotopic faces of the endocyclic double bonds in 11 (t1/2 4 h,. cf. Scheme 3) are reduced much faster. A rationalization of the data can be obtained formulating tertiary alkylcobalamins as intermediates. Of the oxime 6 (cf. Scheme 2) and the p- bromobenzoate 23 (cf. Scheme 5) the structures have been determined by X-ray analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670306
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  • 4
    Electronic Resource
    Electronic Resource
    Stoffwechselprodukte von Mikroorganismen 226. Mitteilung225. Mitteilung s. [1]. Versuche zur Strukturaufklärung von Niphimycin, 3. Teil. Identität von Scopafungin mit Niphimycin I und Lage des Malonylrestes in Niphimycin und CopiamycinHerrn Dr. Arnold Brossi, Bethesda, Md., zum 60. Geburtstag gewidmet (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 696-705 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Structural Elucidation of Niphimycin, Part 3. Identity of Scopafungin and Niphimycin I. Position of the Malonyl Residue of Niphimycin and CopiamycinThe identity of scopafungin with niphimycin I was proven by spectroscopic and chromatographic methods and by common degradation products. The position of the malonyl residue in niphimycin I (9) and in copiamycin (14) was deduced by 1H-NMR spin-decoupling experiments of a degradation product (10).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670309
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  • 5
    Electronic Resource
    Electronic Resource
    Synthesen, chemische und elektrische Eigenschaften von Tetrathiafulvalen mit 1,6-Methano[10]annulen-Partialstruktur und von Chalcogendiimid-derivatenFrau Prof. Dr. Dr. E.h. M. Becke-Goehring, Heidelberg, mit herzlichen Wünschen zum 70. Geburtstag gewidmet (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 574-582 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses, Chemical and Electrical Properties of Tetrathiafulvalene with a 1,6-Methano[10]annulene Moiety and of Chalcogendiimide-DerivativesThe synthesis of the tetrathiafulvalene 6 has been described: the reaction of 1 with the benzenedithoil 2 yielded the bis-dithioacetal 3 of 1,6-methano[10]annulene-dicarbaldehyde 1. The oxidation of 3 in the presence of HBF4 in Et2O yielded the salt 4, elimination of a hydride anion with triphenylmethylium tetrafluoroborate the salt 5, and elimination of a proton in 5 with Et3N the tetrathiafulvalene 6 with a 1,6-methano[10]annulene moiety. The spectroscopic and electrochemical properties of 6 are described, and also the syntheses and properties of charge-trasnfer complexes 7 and 8, including the properties of electric conductivity of 7 and 8. the syntheses of 9-13 are reported and also their spectroscopic properties.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670225
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  • 6
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    Electronic Resource
    Voltammetrische Untersuchungen der Oxydation der symmetrischen Triazacarbocyanine in Acetonitril (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 765-769 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Voltammetric Investigations on the Oxidation Step of Symmetrical Triazacarbocyanine Dyes in Acetonitrile SolutionThe oxidation behaviour of twelve symmetrical triazacarbocyanine dyes with different heterocycles in MeCN (containing tetrabutylammonium perchlorate) has been investigated by means of dc-, ac- and cyclic triangular wave voltammetry. The oxidation mechanism has been found to be of the type ec, with the electrochemical step being reversible to irreversible. Oxidation potentials and transfer coefficients have been measured (E1/2 1.60 to 2.12 V vs. Ag/AgCl) and compared with known properties of carbocyanines. The effect of substituents X has been studied on the compounds 1,3-diethyl-2-[3-(1,3-diethyl-5-X-benzimidazolin-2-ylidene)-1-triazeno]-5-X-benzimidazolium tetrafluoroborate ((1a(X)) and 3-ethyl-2-[3-ethyl-5-X-Δ4-1,3-thiazolin-2-ylidene)-1-triazeno]-5-X-1,3-thiazolium tetrafluoroborate (1g(X)), and ρ-values of 0.425 and 0.565 V, respectively, have been found.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670317
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  • 7
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    Electronic Resource
    Enantioselective synthesis of (+)- and (-)-cis-2-methyl-4-propyl-1,3-oxathiane and their olfactive properties (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 947-952 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enantioselective synthesis of (+)- and (-)-cis-2-methyl-4-propyl-1,3-oxathine 8 and 9 form (E)-2-hezen-1-ol (1) as common starting material is described. The two enantiomeric forms exhibit different organoleptic properties.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670405
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  • 8
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    Electronic Resource
    Plectranthone A, B, C und D. Diterpenoide Phenanthren-1,4-dione aus Blattdrüsen einer Plectranthuus sp. (Labiatae) (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 1003-1011 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plectranthons A, B, C, and D. Diterpenoid Phenanthrene-1,4-diones from Leaf-glands a Plectranthus sp. (Labiatae)The following structures of four new 1,4-phenanthraquionones, isolated in minute amounts from the coloured leaf-glands of a Plectranthus sp. obtained from the borders of Lake Kiwu2, Rwanda, are proposed: plectranthon A (1; 3-hydroxy-5, 7,8-trimethyl-2-(2-propenyl)phenanthrene-1, 4-dione), plectranthon B (2; 2-(2ξ-acetoxypropyl)-3-hydroxy-5,7,8-trimethylphenanthrene-1,4-dione), plextranthon C (3; 3-hydroxy- 7,8-diemethyl-2-(2-propenyl)phenanthrene-1,4-dione), and plectranthon D (4; 3-hydroxy-7,8,10-trimethyl-2-(2-propenyl)phenanthrene-1,4-dione). 2-(2ξ-Hydroxypropyl)-3,6-dihydroxy-5,7,8-trimethylphenanthrene-1,4-dione (11), a compound very similar to 1-4, was prepared by a Wagner-Meerwein, rearrangement of coleon E (5). Biogenetically, the plectranthons are derived from abietanoic precursors. The compounds 1, 2 and 4 are the first natural C20-phenanthrenes of diterpenoid origin.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670412
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  • 9
    Electronic Resource
    Electronic Resource
    Vicarious Nucleophilic Substitution of Hydrogen in Nitropyridines by α-Chloroalkyl Phenyl Sulfone Carbanions (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 8-14 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stellvertretende nucleophile Substitution von Wasserstoff in Nitropyridinen durch α-Chloralkylphenylsulfon-CarbanionenNitropyridine und Chlornitropyridine reagieren mit Carbanionen von α-Chloralkylphenylsulfonen unter „stellvertretender nucleophiler Substitution“ von Wasserstoff in o- und p-Stellung zur Nitrogruppe. Als allgemeine Regel wurde beobachtet, daß die „stellvertretende Substitution“ des Wasserstoffs rascher als die nucleophile Substitution von entsprechend aktiviertem Halogen erfolgt. Die Orientierung der Wasserstoff-Substitution wird diskutiert.
    Notes: Nitropyridines and chloronitropyridines react with carbanions of α-chloroalkyl phenyl sulfones yielding products of the vicarious nucleophilic substitution of hydrogen at positions ortho and para to the nitro group. A general rule that the vicarious substitution of hydrogen proceeds faster than the nucleophilic substitution of equally activated halogen is observed. The orientation of the hydrogen substitution is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840103
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  • 10
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    Carbonyl and Thiocarbonyl Compounds: Reactions of 4-Chloroxanthione with Diazoalkanes and Compounds containing Active Hydrogen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 191-195 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbonyl und Thiocarbonylverbindungen: Reaktionen von 4-Chlorxanthion mit Diazoalkanen und Ch-aciden verbindungenWährend 4-Chlorxanthion 1 mit Diazomethan das Dithiolan 2 ergibt, entstehen mit anderen Diazoalkanen die Episulfide 3-5, deren Entschwefelung zu den entsprechenden Ethylenen 6-7 führt. Malononitril und Cyanessigsäure-ethylester reagieren mit 1 zu den Cyanderivaten 8a, b. Mit Hydrazinen und p-Toluidin ergibt 4-Chlorxanthion (1) die Hydrazone 9a, b und die Schiff-Base 9c. In Abhängigkeit von den Reaktionsbedingungen liefert die Oxidation des Hydrazons 9a die Diazoverbindung 10 oder das Ketazin 11. Hydroxylamin reagiert mit 1 zum Oxim 9d, das mit Phenylisocynat zum N-Phenylcarbamat 9e reagiert.
    Notes: While 4-chloroxanthione 1 gives with diazomethane the dithiol 2, it reacts with other diazoalkanes to give the episulfides 3-5, desulfurization of which forms the ethylenes 6 and 7. Malononitrile and ethyl cyanoacetate react with 1 to give the cyano derivatives 8a, b. With hydrazines and p-toluidine, 4-chloroxanthione (1) give the hydrazones 9a, b and the Schiff's base 9c, respectively. The hydrazone 9a on oxidation may give either the corresponding diazo compound 10 or the ketazine 11 according to the reaction conditions. The title compound 1 reacts with hydroxylamine to yield the oxime 9d which forms the N-phenylcarbamate 9e when treated with phenyl isocyanate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840119
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  • 11
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    Reactions of 4-Chloro-9H-xanthene-9-thione with Tetrachloro-o-benzoquinone (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 196-198 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaktionen von 4-Chlor-9H-xanthen-9-thion mit Tetrachlor-O-benzochinon4-Chlor-9H-xanthen-9-thion (1) reagiert mit Tetrachlor-o-benzochinon zu dem cyclischen Acetal 2. Zur Struktursicherung wurde 2 auf unabhängigen Wegen aus Tetrachlor-o-benzochinon und 4-Chlor-9-diazo-9H-xanthen oder 4-Chlor-9H-xanthen-9-on-hydrazon sowie aus Tetrachlorbrenzcatechin und 4,9,9-Trichlor-9H-xanthen synthetisiert. Die Spaltung der Acetalgruppe in 2 mit Salzsäure, Malononitril, Cyanessigsäure-ethylester und Hydrazinhydrat wurde studiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840120
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  • 12
    Electronic Resource
    Electronic Resource
    Polyhydroxyamine via Diensynthese mit Nitrosoverbindungen, IX. trans-6-Azido-1,3-cyclohexadien-5-ol als Edukt bei der Synthese von Kondurdiamin- und Streptaminisomeren (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 203-212 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polyhydroxyamino Compounds via Diene Synthesis with Nitroso compounds, IX.  -  trans-6-Azido-1,3-cyclohexadien-5-ol as educt for the Synthesis of Kondurodiamine and Streptamine IsomersThe diaminodideoxykonduritols 8a, 8b, and 9 as well as the analogs 10 and 11 of Streptamine have been synthesized starting with O,N-5,6-disubstituted cyclohexadienes.
    Notes: Die Diaminodidesoxykondurite 8a, 8b und 9 sowie die Streptaminanalogen 10 und 11 werden ausgehend von O,N-5,6-disubstituierten Cyclohexadienen synthetisiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840202
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  • 13
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    Electronic Resource
    Thiophosphatidsäureester mit C—S—P-Bindung (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1-7 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiophosphatidic Acid Esters Containing a C—S—P BondThiophosphatidic acid and the following thiophosphatidic acid esters containing a C—S—P bond were synthesized: O,O-dimethyl S-(2,3-distearoyloxypropyl) thiophosphate (4). O-methyl S-(2,3-distearoyloxypropyl) thiophosphoric acid (4a), and O,O-bis(trimethylsilyl) S-(2,3-distearoyloxypropyl) thiophosphate (6). The structures were proved by NMR and IR spectra. It was demonstrated that O,O-dimethyl S-(2,3-isopropylidenedioxypropyl) thiophosphate (3) can be obtained from 2,3-isopropylidenedioxy-1-propanethiol (1) in good yield and acylated to yield 4.
    Notes: Thiophosphatidsäure und folgende Thiophosphatidsäureester mit C—S—P-Bindung wurden synthetisiert: Thiophosphorsäure-O,O-dimethyl-S-(2,3-distearoyloxypropyl)ester (4), Thiophosphorsäure-O-methyl-S-(2,3-distearoyloxypropyl)ester (4a) und Thiophosphorsäure-O,O-bis(trimethylsilyl)-S-(2,3-distearoyloxypropyl)ester (6). Die Strukturen wurden durch NMR- und IR-Spektren bestätigt. Es wurde gezeigt, daß Thiophosphorsäure-O,O-dimethyl-S-(2,3-isopropylidendioxypropyl)ester (3) mit guter Ausbeute aus 2,3-Isopropylidendioxy-1-propanthiol (1) erhalten und zu 4 acyliert werden kann.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840102
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  • 14
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    Synthese von 4-Penten-4-oliden (γ-Methylen-γ-butyrolactonen) über 4-Pentensäuren (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 15-30 
    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 4-Penten-4-olides (γ-Methylene-γ-butyrolactones) vis 4-Pentenoic Acids4-Penten-4-olides (γ-Methylene-γ-butyrolactones) 7 are easily accessible starting from allylic alcohols 1, which on ortho ester Claisen rearrangement and hydrolytic work-up furnish 4-pentenoic acids 5. The latter on iodolactonization and hydrogen iodide elimination by means of 1,8-diaza-bicyclo[5.4.0]undec-7-ene (DBU) furnish 7, in good over-all yield and with variable substitution patterns.  -  Iodolactonization under kinetic control shows moderate 1,2- or 1,3-asymmetric induction (≳ 3:1 and ca. 2:1, respectively). The composition of the iodolactone mixtures 6 as well as the individual relative configurations are deduced from 1H and 13C NMR data.  -  Similarly, the spirobipentenolide 13 is obtained starting from diethyl diallylmalonate (9) via 11 resulting from ester iodocyclization.
    Notes: 4-Penten-4-olide (γ-Methylen-γ-butyrolactone) 7 sind aus Allylalkoholen 1 durch Orthoester-Claisenumlagerung und Hydrolyse zu 4-Pentensäuren 5, anschließende Iodlactonisierung und HI-Abspaltung mit 1,8-Diazabicyclo[5.4.0]undec-7-en (DBU) in guter Gesamtausbeute und variablem Substitutionsmuster leicht zugänglich.  -  Die Iodlactonisierung unter kinetischer Kontrolle zeigt mäßige 1,2- oder 1,3-asymmetrische Induktion (≳ 3:1 bzw. ca. 2:1). Die Zusammensetzungen der Iodlactongemische 6 sowie die relativen Konfigurationen werden aus 1H- und 13C-NMR-Daten abgeleitet.  -  Das Spirobipentenolid 13 wird in ähnlicher Weise aus Diallylmalonsäure-diethylester (9) über 11 (durch Ester-Iodlactonisierung) erhalten.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840104
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  • 15
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    Studien auf dem Gebiet der Naturstoffchemie, 89. Halogenierungsreaktionen des 1,3-Dihydroxy-10-methyl-9(10H)-acridinons und seiner Ether  -  eine einfache regiospezifische Synthese des Acronycins (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 31-38 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Chemistry of Natural Organic Materials, 89.  -  halogenation Reactions of 1,3-Dihydroxy-10methyl-9(10H)-acridinone and its Ethers  -  A Simple Regiospecific Synthesis of AcroyncineIodination of 1,3-dihydroxy-10-methyl-9-acridone (2c) and its ethers 2a and 2b gave the corresponding 2-iodo derivatives 3a-c. Bromination of 2a with NBS yielded 2-bromo-(10), 4-bromo- (11), as well as small amounts of 2,4-dibromo-1,3-dimethoxy-10-methyl-9-acridone (12). Under the same conditions from 2c 2-bromo-1,3-dihydroxy-10-methyl-9-acridone (13) has been obtained. Chlorination of 2a with SO2Cl2 in CHCl3 gave-4-chloro- (14) and 2,4-dichloro-1-hydroxy-3-methoxy-10-methyl-9-acridone (15). The reaction of 3b with copper(I) phenyl- and copper(I) isopropenylacetylide yielded the corresponding 2-substituted 4-methoxy-6-methylfuro[2,3-α]acridin-11(6H)-ones 6a and 6b, respectively. From the condensation reaction of 3c with 3-chloro-3-methyl-1-butyne noracronycine (8) has been obtained.
    Notes: Die I2/HIO4-Iodierung von 1,3-Dihydroxy-10-methyl-9-acridon (2c) und seiner Ether 2a und 2b ergab die entsprechenden 2-Iod-Derivate 3a-c. Bromierung von 2a mit NBS führte zu 2-Brom-(10), 4-Brom-(11) sowie geringen Mengen von 2,4-Dibrom-1,3-dimethoxy-10-methyl-9-acridon (12). Unter denselben Bedingungen lieferte 2c 2-Brom-1,3-dihydroxy-10-methyl-9-acridon (13). Chlorierung von 2a mit SO2Cl2 in CHCl3 ergab 4-Chlor-(14) und 2,4-Dichlor-1-hydroxy-3-methoxy-10-methyl-9-acridon (15). Umsetzen von 3b mit Kupfer(I)-phenyl- bzw. Kupfer(I)-isopropenylacetylid führte zu den 2-substituierten 4-Methoxy-6-methylfuro[2,3-α]acridin-11(6H)-onen 6a und 6b. Die Reaktion von 3c mit 3-Chlor-3-methyl-1-butin ergab Noracronycin (8).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840105
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  • 16
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    Synthese des Methylethers der Herzgift-Methylreduktinsäure aus D-Glucose (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 66-77 
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    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 Methyl Ether of “Herzgift-Methylreduktinsäure” Starting from D-GlucoseThe methyl ether 5 of „Herzgift-Methylreduktinsäure“ (2), a degradation product of the Calotropis cardenolides, has been synthesized starting from D-glucose as the chiral pool. The configuration of 2, previously based on the results of degradation, is confirmed by the synthesis of 5.
    Notes: Der Methylether 5 der „Herzgift-Methylreduktinsäure“ (2), eines Abbauproduktes der Calotropis-Cardenolide, wird in einer mehrstufigen Synthese aus D-Glucose als chiralem Ausgangsmaterial hergestellt. Damit wird die durch Abbaureaktionen getroffene Konfigurationszuordnung für 2 durch Synthese von 5 bestätigt.
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    URL: http://dx.doi.org/10.1002/jlac.198419840108
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    (Aminoethinyl)metallierungen, 13. Synthese und Reaktionen von 3-Aminopropiolamidinen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 85-97 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aminoethynyl Metallations, 313.  -  Synthesis and Reactions of 3-AminopropiolamidinesThe lithium aminoacetylides 1 react with the carbodiimides 2 to give the lithium propiolamidinates 3, which are hydrolyzed to yield the 3-aminopropiolamidines 4. 3 can directly be converted into the persubstituted ynamine carboxamidines 5 by adding methyl iodide. The amidines 4 with less activated C/C-triple bonds (NR1R2 = N(Me)Ph or NPh2) react with thioformaldehyde dioxide or with diphenyl ketene exclusively at the NH group with formation of the sulfonamides 6 or of an carboxamide 7. The more reactive (diethylaminoacetylene)carboxamidine 4h adds a second molecule of ketene to furnish the cyclobutenone derivative 8. The propiolamidine 4b with a diphenylamino group at the triple bond reacts with concentrated hydrochloric acid under formation of the amidinium salt 9 and partly by addition of a second molecule of hydrochloride to the triple bond to give 10. Adding tosyl azide to 4 we obtained via the triazole 11 by two successive 1,5-cyclizations the 4-amidino-1,2,3-triazoles 12. The 3-aminopropiolamidines 4 bearing at least one aryl group in the amidine moiety cyclize to give the 2,4-diaminoquinolines 17 if they are chromatographed on silica gel. The same or analogously substituted quinolines 17 are obtained by the reaction of the simple ynamines 15(H, Me, or Ph in the β-position) with the corresponding carbodiimides 2 2-Anilino-4-diethylamino-3-methylquinoline (17e) is hydrolyzed in acidic solution to give the 4-quinolone derivative 19.
    Notes: Die Lithium(aminoacetylide) 1 reagieren mit den Carbodiimiden 2 zu den Lithiumpropiolamidinaten 3, deren Hydrolyse die 3-Aminopropiolamidine 4 liefert. Mit Methyliodid entstehen aus 3 die persubstituierten Inamincarboxamidine 5. Die Amidine 4 reagieren bei geringer Aktivierung der Dreifachbindung [NR1R2 = N(Me)Ph oder NPh2] mit Sulfen oder mit Diphenylketen ausschließlich an der NH-Gruppe unter Sulfonamid- bzw. Carboxamidbildung (s. 6 und 7). Das reaktivere (Diethylaminoacetylen)carboxamidin 4h addiert bei der Umsetzung mit Diphenylketen zusätzlich ein Ketenmolekül an der Dreifachbindung zum Cyclobutenonderivat 8. Der Propiolamidinvertreter 4b mit Diphenylaminogruppe an der Dreifachbindung reagiert mit konz. Salzsäure unter Bildung des Amidiniumsalzes 9, und unter Addition von Chlorwasserstoff an die Dreifachbindung zu 10, Mit Tosylazid erhält man nach der Triazolbildung 11 in zwei aufeinanderfolgenden 1,5-Cyclisierungen die 4-Amidino-1,2,3-triazole 12. Die 3-Aminopropiolamidine 4 mit mindestens einer Arylgruppe im Amidinteil cyclisieren im Kontakt mit Silicagel zu den 2,4-Diaminochinolinen 17. Die gleichen oder analog substituierten Chinoline 17 erhält man auch durch Umsetzung der einfachen Inamine 15 (Wasserstoff, Methyl- oder Phenylgruppen in β-Position) mit den entsprechenden Carbodiimiden 2. 2-Anilino-4-diethylamino-3-methylchinolin (17e) wird in saurem Medium zum 4-Chinolonderivat 19 hydrolysiert.
    Additional Material: 3 Tab.
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    Synthese der Pterocarpane aus Swartzia laevicarpa (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 127-132 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Pterocarpan Constituents of Swartzia laevicarpaThe synthesis of 2,8-dihydroxy-3,4-dimethoxy- (1), 2,8-dihydroxy-3,9,10-trimethoxy- (2), 8-hydroxy-3,4,9,10-tetramethoxy- (3), and 2,8-dihydroxy-3,4,9,10-tetramethoxypterocarpan (4)  -  each of them as racemate  -  confirmed the constitution of four new pterocarpans isolated from Swartzia laevicarpa.
    Notes: Durch die eindeutige Synthese von jeweils racemischem 2,8-Dihydroxy-3,9-dimethoxy- (1), 2,8-Dihydroxy-3,9,10-trimethoxy-(2), 8-Hydroxy-3,4,9,10-tetramethoxy-(3) und 2,8-Dihydroxy-3,4,9,10-tetramethoxypterocarpan (4) wurde die Konstitution von vier neuen, aus Swartzia laevicarpa isolierten Pterocarpanen bestätigt.
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  • 19
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    Diastereoselektive Synthese von (1RS)-endo-Brevicomin (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 147-156 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diastereoselective Synthesis of (1RS)-endo-Brevicomin(1RS-endo-Brevicomin (1) is synthesized starting from trans-1-bromo-2-pentene. Synthetic key step is the diastereoselective linkage of erythro-2,3-butanediol to 3,3-dimethoxy-1-(phenylsulfonyl)-butane or methyl 4,4-dimethoxypentanoate.
    Notes: (1RS)-endo-Brevicomin (1) wird ausgehend von trans-1-Brom-2-penten synthetisiert. Schlüsselreaktion ist die diastereoselektive Verknüpfung von erythro-2,3-Butandiol mit 3,3-Dimethoxy-1-(phenylsulfonyl)butan oder 4,4-Dimethoxypentansäure-methylester.
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  • 20
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    Cycloarene, eine neue Klasse aromatischer Verbindungen, IV. Versuche zur Synthese des Cyclo[d.e.e.d.e.e.d.e.e]nonakisbenzens und des Cyclo[d.e.d.e.d.e.d.e.d.e]decakisbenzens (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 742-760 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloarenes, a New Class of Aromatic Compounds, IV. - Attempts to Synthesize cyclo-[d.e.e.d.e.e.d.e.e]nonakisbenzene and cyclo[d.e.d.e.d.e.d.e.d.e]decakisbenzeneWith the aim to synthesize 3 the dithiaphane 5 was prepared from which via 6 the [2]anthraceno[2]benzo[c]phenanthrenophane 10 was obtained. The corresponding [2.2]phane-diene 11 was prepared from 5 via 12 and 13. The conformations of 5, 10, and 11 yielded 14 which was dehydrogenated to yield the new aromatic system 15. The second internal ring closure to 3 so far did not succeed. - As precursors for the synthesis of 4 the [2]dibenzo[a, j]anthraceno[2]anthraceno[2]phenanthrenophanes 19 and 20 as well as the corresponding [2.2]phane-dienes 23 and 24 were prepared via 18.Attempts to cyclodehydrogenate to 4 failed. In this context the conformations of 19, 20, 23, and 24 are discussed based on 1H NMR spectra.
    Notes: Mit dem Ziel der Synthese von 3 wurde das Dithiaphan 5 dargestellt, das über 6 in das [2]Anthraceno[2]benzo[c]phenanthrenophan 10 übergeführt wurde. Das entsprechende Phandien 11 wurde aus 5 über 12 und 13 erhalten. Die Konformationsverhältnisse von 5, 10 und 11 werden anhand der 1H-NMR-Spektren diskutiert. - Aus 11 entstand durch nicht-oxidative Photocyclisierung 14, das zu dem neuen aromatischen Bindungssystem 15 dehydriert wurde. Der zweite innere Ringschluß zu 3 gelang bisher nicht. - Als Vorstufen für die Synthese von 4 wurden über 18 die [2]Dibenz[a, j]anthraceno[2]phenanthrenophane 19 und 20 sowie die entsprechenden [2.2]Phandiene 23 und 24 dargestellt. Versuche der Cyclodehydrierung zu 4 schlugen fehl. In diesem Zusammenhang werden die Konformationsverhältnisse von 19, 20, 23 und 24 auf der Basis von 1H-NMR-Daten diskutiert.
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    Selektive Reaktionen von Hydroazulenen: Chirale Norcaranderivate über die Umsetzung eines Dihydroazulens mit Singulettsauerstoff (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 773-782 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Selective Reactions of Hydroazulenes: Chiral Norcarane Derivatives by the Reaction of a Dihydroazulene with Singlet OxygenPhotosensitized oxygenation of the dihydroazulene 6 affords the two peroxides 7 and 8 in good overall yield. The major product is derived from the “norcaradiene” of 6. The cycloaddition with singlet oxygen occurs stereospecifically. Consecutive reaction of 7 yield chiral norcarane derivatives in stereospecific ways. Thus, by thermolysis of 7 the bisepoxide 10 is formed; reaction of 7 with triethylamine leads to the hydroxyketone 11 with MnO2 the homoquinone 13 is formed. The structures are established by spectroscopic methods.
    Notes: Die Umsetzung des Dihydroazulens 6 mit Singulettsauerstoff ergibt die beiden Peroxide 7 und 8. Das Hauptprodukt 7 leitet sich vom “Norcaradien” des Hydroazulens 6 ab. Die 1O2-Addition erfolgt stereoselektiv. Folgereaktionen von 7 ergeben chirale Norcaranderivate: Thermolyse führt zum Bisepoxid 10, mit Triethylamin entsteht das Hydroxyketon 11 und Triphenylphosphan führt unter Sauerstoffabspaltung zu den Vinyloxiranen 12a und 12b. Bei diesen Reaktionen wird jeweils nur ein Diastereomeres gebildet. Die Oxidation von 11 mit Mangandioxid ergibt das Homochinon 13. Für sämtliche Reaktionsprodukte sind spektroskopische Daten angegeben.
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    Synthesen von (+)-Oudemansin und (+)-Epioudemansin aus enantiomerenreinen Vorstufen; absolute Konfiguration des natürlichen (-)-Oudemansins (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 791-801 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of (+)-Oudemansin and (+)-Epioudemansin Starting from Enantiomerically Pure Precursors; Absolute configuration of the Naturally Occurring (-)OudemansinThe syntheses of the four optically pure methyl (E)-3-hydroxy-2-methyl-5-phenyl-4-pentenoates (+)- and (-)-5 as well as (+)- and (-)-6 were achieved by consecutive methylation and protonation of enolates, starting from (+)- and (-)-4. The esters (+)-6 and (-)-5 are used as starting materials to synthesize (+)-oudemansin [(+)-3] and (+)-epioudemansin [(+)-9].
    Notes: Die Darstellung der vier optisch reinen (E)-3-hydroxy-2-methyl-5-phenyl-4-pentensäure-methylester (+)- und (-)-6 gelingt durch aufeinanderfolgende Methylierung und Protonierung von Esterenolaten, ausgehend von (+)- und (-)-4. Die Ester (+)-6 und (-)-5 werden für Synthesen von (+)-Oudemansin [(+)-3] und (+)-Epioudemansin [(+)=9] eingesetzt.
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    URL: http://dx.doi.org/10.1002/jlac.198419840415
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    Flexible und effektive Synthese für 4-Oxo-2-alkensäuremethylester (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 820-827 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Flexible and efficient Synthesis of Methyl 4-Oxo-2-alkenoatesThe title compounds E are obtained in good yield by low temperature ring cleavage of the easily available methyl 2-siloxycyclopropanecarboxylates C with bromine and subsequent elimination of hydrogen bromide. Due to the variability of C a high flexibility concerning substituents R1-R4 in products E is guaranteed. 2-Alkyl- and 2-methylthio-substituted olefins are thus effectively synthesized. In several cases the initally formed methyl 2-bromo-4-oxoalkanoates F are stable enough to be isolated in high yield.
    Notes: Aus den leicht zugänglichen 2-Siloxycyclopropancarbonsäure-methylestern C erhält man durch Ringöffnung mit Brom bei tiefer Temperatur und anschließender Bromwasserstoffeliminierung die Titelverbindungen E in guten Ausbeuten. Aufgrund der Variationsmöglichkeiten bei C ergibt sich bei den Produkten E eine große Flexibilität bezüglich der Reste R1-R4. So sind auch 2-alkyl- und 2-methylthiosubstituierte Olefine effektiv darstellbar. In einigen Fällen sind die primär gebildeten 2-Brom-4-oxoalkansäure-methylester F so stabil, daß sie in hoher Ausbeute isolierbar sind.
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    Zur Ringöffnung von 2-(Trimethylsilylmethyl)cyclopropancarbonsäure-methylester (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 828-830 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ring Opening of Methyl 2-(Trimethylsilylmethyl)cyclopropanecarboxylateThe reactivity of the title compound 5 is compared with that of methyl 2-siloxycyclopropanecarboxylates. 2. Whereas these are cleaved under various conditions, the less activated derivative 5 undergoes ring opening to yield methyl pentenoate (6a) only with sources of “free” flouride-like tetra-n-butylammonium fluoride.
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    URL: http://dx.doi.org/10.1002/jlac.198419840418
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    1-Aza- und 1,9-Diazatriptycene (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 381-388 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1-Aza- and 1,9-DiazatriptycenesThe polycyclic 1,5-diketone 4 is synthesized via the enamine 2 from ketone 1 and phenyl vinyl ketone (3). On reacting the 1,5-diketone 4 with hydroxylamine the expected ring closure to the 1-azatriptycene 6 competes with a ring cleavage by an anomalous Beckmann rearrangement of the oxime yielding the intermediate nitrile 10 which cyclizes to afford the β-anthracenyl-α-aminopyridine 7. [4 + 2] Cycloaddition of dehydrobenzene, generated by diazotation of anthranilic acid, with the pyrido[3,2-g]quinolines 13a, b produces the diazatriptycenes 15a, b.
    Notes: Aus dem Keton 1 wird via Enamin 2 mit Phenylvinylketon (3) das polycyclische 1,5-Diketon 4 hergestellt. Bei dessen Umsetzung mit Hydroxylamin konkurriert der erwartete Ringschluß zum 1-Azatriptycen 6 mit einer Ringöffnung durch anomale Beckmann-Umlagerung des Oxims 9 zum intermediären Nitril 10, das zum β-Anthracenyl-α-aminopyridin 7 cyclisiert. [4 + 2]-Cycloaddition von Dehydrobenzol, das durch Diazotierung von Anthranilsäure erzeugt wird, mit den Pyrido[3,2-g]chinolinen 13a, b ergibt die Diazatriptycene 15a, b.
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    Mehrstufige reversible Redoxsysteme, XXXV. Voltammetrie vinyloger Polyene mit gekreuzt konjugierten Endgruppen und UV/VIS-Spektroskopie ihrer Radikalanionen und -kationen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 354-369 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Multistep Reversible Redox Systems, XXXV.  -  Voltammetry of Vinylogous Polyenes with Cross-Conjugated End Groups and UV/VIS Spectroscopy of their Radical Anions and CationsMost of the polyenes 1-5, especially of the vinylogous 2.n(n = 0-4) and 5.n(n = 1-4) are as well reversibly reduced as oxidized in two steps. As expected the large semiquinone formation constants decrease with increasing chain length (2: KSEMc = 1013-107; KSEMa = 1011-101). The UV/VIS spectra of the radical anions and cations of system 2.n, generated in solution, belong to the violene type; Δλmax ≈ 135 nm (SEMc) and Δλmax ≈ 160 nm (SEM). The potentials of 5.n and the UV/VIS spectra of the radicals of 5.1 point towards twisted molecules. The systems 2.n are the first polyenes which can exist in five oxidation levels and which form persistent radical anions and cations. The redox potentials of 2.n and the UV/VIS spectra of the radical ions are in accordance with the predictions of the Hückel theory.
    Notes: Die Mehrzahl der Polyene 1-5, insbesondere der Vinylogen 2.n (n = 0-4) und 5.n (n = 1-4) werden sowohl reversibel zweistufig reduziert als auch oxidiert. Erwartungsgemäß nehmen die großen Semichinonbildungskonstanten mit wachsender Kettenlänge ab (2: KSEMc = 1013-107; KSEMa = 1011-101). Die UV/VIS-Spektren der in Lösung erzeugten Radikalanionen und-kationen des Systems 2 (n = 0-4) sind vom Violentyp mit Δλmax ≈ 135 nm (SEMc) und Δλmax ≈ 160nm (SEM). Die Potentiale des Systems 5.n sowie die UV/VIS-Spektren der Radikal-Ionen aus 5.1 weisen auf Verdrillung hin. Mit 2.n liegen erstmals Polyene vor, die in fünf Oxidationsstufen existieren können und deren Radikal-Ionen persistente Lösungen bilden. Sowohl die Redoxpotentiale von 2.n als auch die UV/VIS-Spektren der Radikal-Ionen entsprechen den Erwartungen der Hückel-Theorie.
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    Konformationsanalyse, XXIV. Bestimmung der Konformationen von Tri- und Tetrasaccharid-Sequenzen der Core-Struktur von N-Glycoproteinen. Problem der (1 → 6)-glycosidischen Bindung (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 951-976 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Confomational Analysis, XXIV. - determination of the Conformations of Tri-and Tetrasaccharide Sequences of N-Glycoproteins. The problem of the (1 → 6)-glycosidic BondThe preferred solution conformations of the saccharides α-D-Man(1 → 3)-β-D-Man(1 → 4)-D-GIcNAc (1), α-D-Man(1 → 6)-β-Man(1 → 4)-D-GIcNAc (2), and α-D-Man(1 → 3)[α-D-Man(1 → 6)]lβ-D-Man(1 → 4)-D-GIcNAc3), which are known as parts of the core structure of N-glycoproteins, could be established by use of HSEA calculations (HSEA: Hard-Sphere Exo-Anomeric) with the new program GESA (= Geometry of Saccharides) in connection with 1H NMR investigations like NOE experiments, spin-lattice relaxation-time measurements and the observation of selective deshieldings. (1 → 3)- and (1 → 4)-glycosidic bonds show one strongly preferred conformation. The greater flexibility of the (1 → 6)-glycosidic bonds show one strongly preferred conformation. The greater flexibility of the (1 → 6)-glycosidic bond will be discussed in details. For the spectra analysis various 2-D techniques have been used.
    Notes: Von den Sacchariden α-D-Man(1 → 3)-β-D-Man(1 → 4)-D=-GICNAc (1), α-D-Man(1 → 6)-β-D-Man(1 → 4)-D-GIcNAc(2) und α-D-Man(1 → 3)[α-D-Man(1 → 6)]-β-D-Man(1 → 4)-D-GlcNAc(3), die als Core-Struktur in N-Glycoproteinen vorkommen, wurden durch HSEA-Berechnungen (HSEA: Hard-Sphere Exo-Anomeric) mit dem neuen GESA-Programm (GESA: Geometry of Saccharides) die bevorzugten Konformationen bestimmt. Mit Hilfe von 1H-NMR-Experimenten, nämlich NOE-Experimenten, Spin-Gitter-Relaxationszeitmessungen und der Beobachtung selektiver Entschirmungen, ließen sich diese Konformationen in Lösung bestätigen. (1 → 3)- und (1 → 4)-glycosidische Bindungen weisen eine stark bevorzugte Konformation auf. Die weitaus größere Flexibilität der (1 → 6)-glycosidischen Bindung wird besonders diskutiert. Zur Analyse der Spektren wurden verschiedene 2-D-NMR-Techniken angewandt.
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    URL: http://dx.doi.org/10.1002/jlac.198419840514
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    Reaktionen mit Isocyaniden. Synthese tiefblauer Farbstoffe aus 1,4-Chinonen und Arylisocyaniden (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1003-1012 
    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 Isocyanides. - Synthesis of Dark-blue Dyes from 1,4-Quinones and Aryl Isocyanides1,4-Benzoquinone reacts with aryl isocyanides 2a-d in boiling toluene or xylene forming darkblue 1:2 and 1:4 adducts, the 4,7-isoindolediones 3a-d and the 1,5- and 1,7-bis(arylamino)-benzodipyrrolediones 4a-c and 5a-c, respectively, which can be separated by chromatography. The structure of the 4-methylphenyl isocyanide adducts 3b, 4b, and 5b is established by NMR spectroscopy. The 1:2 adduct 3b reacts with two moles of 4-methylphenyl isocyanide (2b) affording the isomeric 1:4 adducts 4b and 5b. However, in a similar reaction with 4-chlorophenyl isocyanide (2c) surprisingly only the 1,5-bis(arylamino) derivative 8 is isolated. 1,4-Naphthoquinone (10) reacts with 4-methylphenyl (2b or 4-nitrophenyl isocyanide (2d) to yield the 4,9-benzo[f]isoindoles 11b and d, respectively.
    Notes: 1,4-Benzochinon reagiert mit den Arylisocyaniden 2a-d in siedendem Toluol oder Xylol zu tiefblauen 1:2- und 1:4-Addukten, den 4,7-Isoindoldionen 3a-d bzw. den 1,5- und 1,7-Bis(arylamino)benzodipyrroldionen 4a-c und 5a-c, die chromatographisch getrennt werden. Die Struktur der (4-Methylphenyl)isocyanid-Addukte 3b, 4b und 5b wird NMR-spektroskopisch bewiesen. Das 1:2-Addukt 3b ergibt mit zwei Molen (4-Methylphenyl)isocyanid (2b) die isomeren 1:4-Addukte 4b und 5b; mit (4-Chlorphenyl)isocyanid (2c) wird jedoch überraschenderweise nur das 1,5-Bis(arylamino) Derivat 8 isoliert. 1,4-Naphthochinon (10) bildet mit (4-Methylphenyl)-(2b) bzw. (4-Nitrophenyl)isocyanid (2d) die 4,9-Benzo[f]isoindoldione 11b und d.
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    URL: http://dx.doi.org/10.1002/jlac.198419840518
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    Reaktionen von 1,4-Pentadien-3-onen, 22. Darstellung und Struktur der epimeren 3,5-Diaryl-4-hydroxy-1,4-thiazinan-1,1-dioxide (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1013-1023 
    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 1,4-Pentadien-3-ones, 22. - Synthesis and Structure of the Epimers of 3,5-Diaryl-4-hydroxy-1,4-thiazinane 1,1-DioxidesDistyrylsulfones 1 react with the ambident nucleophile hydroxylamine only by double addition of nitrogen to give 4-hydroxy-1,4-thiazinane derivatives 3. In solution 3 consists of a temperature-dependent equilibrium mixture of two epimers. When heated or when crystallized one of the epimers is depopulated. The above phenomena and structures are elucidated by an X-ray analysis and by NMR spectroscopy.
    Notes: Distyrylsulfone 1 reagieren mit dem ambidenten Nucleophil Hydroxylamin ausschließlich unter doppelter Addition des Stickstoffs zu 4-Hydroxy-1,4-thiazinan-Derivaten 3. Diese bilden in Lösung temperaturabhängige Epimeren-Gleichgewichte. Sowohl beim Erwärmen als auch beim Auskristallisieren erfolgt Depopulation eines Epimers. Strukturen und Phänomene werden durch Röntgenstrukturanalyse und NMR-Spektroskopie geklärt.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198419840519
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    Über die Iodierung von Monosaccharid-Derivaten mit Iodtrimethylsilan (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1052-1055 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Iodation of Monosaccharide Derivatives with IodotrimethylsilaneWith iodotrimethylsilane generated in situ, iodine can be introduced into carbohydrate derivatives with high selectivity. The rate of iodination at the anomeric center of the C-1-substituted 2,3,4,6-tetra-O-acetyl-D-glucopyranoses 1a-d decreases in the following series: OAc 〉 OBz ≈ OH » OCH3. - Hydroxy groups or their ethers 3b, c react distinctively to give the trimethylsilyl ethers, whereas the primary react to yield the 6-deoxy-6-iodo derivatives 5. The 1-O-acetyl-6-hydroxy derivative 6a and its 6-O-trityl ether form 2,3,4-tri-O-acetyl-6-deoxy-6-iodo-α-D-glucopyranosyl iodide (7).
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    URL: http://dx.doi.org/10.1002/jlac.198419840523
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    Versuche zur Synthese des Polystachins (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1068-1077 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Attempted Synthesis of Polystachin[1′RS(3RS)]-1-(2,3-Dihydro-4-hydroxy-6-methoxy-1-benzofuran-3-yl)-2-methyl-1,2-propandiol (21), a partial structure of the title substance 1 was synthetized in 11 steps from phloroglucinol. The key steps were the oxidative rearrangement of the benzylidenacetone derivative 5 by Tl(NO3)3 in methanol to yield the 2-aryl-1,1-dimethoxythane 8 followed by ring closure involving the hydroxy group of 9 liberated by debenzylation. Conversion of 21 into compounds of structure 1 was just as unsuccessful as the synthesis of rac-polystachin (rac-1) from tachrosin (23 via the flavone derivative 29.
    Notes: [1′RS(3RS)]-1-(2,3-Dihydro-4-hydroxy-6-methoxy-1-benzofuran-3-yl)-2-methyl-1,2-propandiol (21), eine Teilstruktur der Titelsubstanz 1, wurde aus Phloroglucin in 11 Schritten synthetisiert. Als Schlüsselreaktion diente die oxidative Umlagerung des Benzalacetonderivates 5 mit Tl(NO3)3 in Methanol zu dem 2-Aryl-1,1-dimethoxyethan 8 gefolgt vom Ringschluß an der durch Entbenzylierung freigesetzten Hydroxygruppe von 9. Die Überführung von 21 in Verbindungen der Struktur 1 blieb ebenso erfolglos wie die Synthese von rac-Polystachin (rac-1) aus Tachrosin (23) über das Flavonderivat 29.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198419840603
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    Zur Chemie des (1α,2β,5β,6α,7β,8β)-3,4-Dioxotricyclo[4.2.1.02,5]-nonan-7,8-dicarbonsäure-dimethylesters (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1109-1116 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Dimethyl [1α,2β,5α,6β,7α,8β]-3,4-Dioxotricyclo[4.2.1.02,5]nonane-7,8-dicarboxylateThe reaction of the cyclobutanedione 1 with urea or substituted thioureas provides by double addition the heterocyclic compounds 2a-d. Hydrazines react to give monohydrazones 3 or, by loss of nitrogen, hydrazones of type 4; no formation of osazones was observed. The reaction with o-phenylenediamine yields the quinoxaline 5. Reduction of 1 with sodium tetrahydroborate leads stereoselectively to the glycol 6. Treatment of 1 with sodium methoxide causes benzilic acid rearrangement yielding the annulated cyclopropanecarboxylate 7 with retention of the configuration of the other carbon atoms. Ring enlargement reactions yield either by radiation of 1 via oxacarbenes compound 14 or by oxidation the anhydride 8 which can be reduced to yield the γ-lactone 9.
    Notes: Die Umsetzung des Cyclobutandions 1 mit Harnstoff oder substituierten Thioharnstoffen führt durch zweifache Addition unter Cyclisierung zu den Imidazolidinonen bzw. -thionen 2a-d. Hydrazinabkömmlinge liefern Monohydrazone 3 oder unter Stickstoffabspaltung Hydrazone vom Typ 4; Osazonbildung wurde nicht beobachtet. Mit o-Phenylendiamin entsteht unter Kondensation das Chinoxalin 5. Die Reduktion von 1 mit Natrium-tetrahydroborat liefert stereoselektiv das Glycol 6. Mit Natriummethanolat findet eine Benzilsäure-Umlagerung zum anellierten Cyclopropancarbonsäureester 7 unter Erhaltung der Konfiguration der restlichen C-Atome statt. Ringerweiterungen lassen sich sowohl photochemisch über Oxacarbene zu 14 als auch durch Oxidation zum Anhydrid 8 durchführen, das durch anschließende Reduktion das Norbornan-anellierte γ-Lacton 9 liefert.
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    Synthesen mit α-metallierten Isocyaniden, LIII. Synthese von 2,3-Epoxy-2-isocyanalkansäure-methylestern (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 608-611 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses with α-Metalated Isocyanides, LIII.  -  Synthesis of Methyl 2,3-Epoxy-2-isocyanoalkanoatesThe title compounds were synthesized from methyl α-isocyanoacrylates 2 with H2O2 (in sodium hydroxide solution) or with m-chloroperbenzoic acid (in methanol/sodium methoxide)
    Additional Material: 1 Tab.
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    Synthesis and Biological Activities of the Antibiotic B 371 and its Analogs (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 600-607 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese und biologische Aktivität des Antibiotikums B 371 und seiner StrukturvariantenDie Synthesen der Titelverbindung 1 und einer Reihe von Strukturvarianten des Typs 4 werden beschrieben. Die antimikrobiellen Aktivitäten dieser Vinylisocyanide, die in β-Position entweder ein Indolderivat oder eine Aryl- oder 2-Thienylgruppe tragen, wurden im Plattentest gegenüber Escherichia coli, Bacillus subtilis und Mucor muhei TÜ 284 geprüft (Tab. 1). Einige der Verbindungen 4 sind stärker wirksam als die natürlich vorkommende Stammverbindung 1.  -  Eine Serie von Alkyl-2-isocyanacrylaten des Typs 5 wurde in den Test einbezogen. Einige davon sind außerordentlich stark aktiv (Tab. 2). Die Aktivität geht in allen Fällen verloren, wenn man die Isocyangruppe zur Formamidogruppe hydrolysiert (4 → 6).
    Notes: The synthesis of the title compound 1 is described as well as the syntheses of a series of structural analogs of type 4. The antimicrobial in vitro activity of these vinyl isocyanides, substituted in β-position either by an indole derivative or by an aryl or 2-thienyl group, was tested against Escherichia Coli, Bacillus subtilis, and Mucor muhei TÜ 284 (Table 1). Some of the compounds 4 display higher activity than the naturally occurring parent compound 1.  -  A variety of alkyl 2-isocyanoacrylates of type 5 were included in the biological test. Some of them display exceptionally high antimicrobial activity (Table 2). Upon conversion of the isocyano group into the formamido group (4 → 6), the biological activity is lost.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198419840317
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    [2.2](2,7)Anthracenophan: Synthese und Konformations-Untersuchungen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 615-617 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2.2](2,7)Anthracenophane: Synthesis and Conformational Studies[2.2](2,7)Anthracenophane (3) was synthesized via the dithia[3.3]anthracenophane 6 and the disulfone 7 derived therefrom. From conformational studies based on 1H NMR a rigid anti conformation was assigned to 3, contrary to 6.
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    URL: http://dx.doi.org/10.1002/jlac.198419840320
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    Mehrstufige, reversible Redoxsysteme, XXXVI. 11,11,12,12-Tetracyan-9,10-anthrachinodimethan (TCNAQ) und seine Derivate: Synthese und Redoxeigenschaften (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 618-621 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Multistep, Reversible Redox Systems, XXXVI.  -  11,11,12,12-Tetracyano-9,10-anthraquinodimethane (TCNAQ) and its Derivatives: Synthesis and Redox PropertiesTitle compounds 3Ba-d are synthesized from the corresponding anthraquinones and malononitrile with titanium tetrachloride/pyridine. By comparison of the potentials and semiquinone formation constants of 1B-3B with those of the corresponding quinones 1A-3A strong distortion of the biscyanomethylene groups in 2B and especially 3B is derived.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198419840321
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    Stereospecific Syntheses of D-Ossamine and D-Tolyposamine (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 636-640 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereospezifische Synthesen von D-Ossamin und D-Tolyposamin2,3,4,6-Tetradesoxy-4-(dimethylamino)-D-threo-hexose (D-Ossamin, 7), der Aminozuckerrest des Pilzmetaboliten Ossamycin und 4-Amino-2,3,4,6-tetradesoxy-D-erythro-hexose (D-Tolyposamin, 12), das Enantiomere des Zuckerrestes des antibiotisch wirksamen Tolypomycins wurden aus D-Glucose über Hex-2-enopyranoside synthetisiert.
    Notes: 2,3,4,6-Tetradesoxy-4-(dimethylamino)-D-threo-hexose (D-ossamine, 7), the amino sugar fragment from the fungal metabolite ossamycin, and 4-amino-2,3,4,6-tetradeoxy-D-erythro-hexose (D-tolyposamine, 12), the enantiomeric constituent of the antibiotic tolypomycin, have been synthesized from D-glucose via hex-2-enopyranosides.
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    URL: http://dx.doi.org/10.1002/jlac.198419840403
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    Synthesen mit aliphatischen Dialdehyden, XXXVIII. Darstellung und Eigenschaften von Cycloalkylmalonaldehyden (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 649-679 
    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, XXXVIII. - Synthesis and Properties of CycloalkylmalonaldehydesVilsmeier formylation cycloalkyl-substituted enol ethers (7, 14a - c, 23) yields the cycloalkylmalonaldehydes 1- 5 for the first time. In solution 1 - 5 with suitable electrophiles and nucleophiles leads to cycloalkyl-substituted open-chain (29, 30), carbocyclic (31) as well as heterocyclic compounds (32-40) with peculiar properties due to the presence of the lipophilic cycloalkyl group.
    Notes: Durch Vilsmeier-Formylierung cycloalkylsubstituierter Enolether (7, 14a - c, 23) werden die Cycloalkylmalonaldehydes 1 - 5 erstmals dargestellt. In Lösung liegen 1 - 5 in der (E)-s-(E)-Enolform als vinyloge Carbonsäuren vor. Reaktion von 1-5 mit geeigneten Elektrophilen und Nucleophilen führt zu cycloalkylsubstituierten offenkettigen (29, 30), carbocyclischen (31) und heterocyclischen Verbindungen (32-40) mit besonderen, durch die lipophile Cycloalkylgruppe hervorgerufenen Eigenschaften.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198419840405
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    (2′→ 5′)- und (3′→ 5′)- Tubercidylyl-tubercidine - Synthese über Phosphit- Triester und Untersuchungen zur Sekundärstruktur, (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 692-707 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (2′→5′) and (3′→′)-Tubercidylyl-tubercidins - Synthesis via Phosphite Triester and Investigation of Secondary StructureThe (2′→ 5′)- and (3′→5′)-linked dinucleoside monophosphates 3e and 2e of tubercidin were synthesized by condensation of the monomers 1c or 1b with dichloromethoxyphosphane. By 1H NMR studies it could be demonstrated that the conformation of these nucleobases is different from that in (3′→ 5′)ApA and (2′→ 5′)ApA. From thermodynamic parameters, as well as from hypochromicity, a stronger base - base interaction in 3e than in 2e was deduced. Single-strand specific nuclease S1 hydrolyses 2e at a much higher rate than (3′→ 5′)ApA demonstrating that the enzyme is sensitive towards modification of the aglycone. Condensation of the 5′-deprotected dimer 3b with the monomer 1c followed by complete deprotection yields (2′→ 5′)TupTuTu (4e), which is an analogue of (2′→ 5′)ApApA, the triphosphate of which is antivirally active.
    Notes: Die (2′→ 5′)- und (3′→ 5′)-verknüpften Dinucleosid-monophosphate 3e und 2e des Tubercidins werden aus den Vorstufen 1b oder 1c und 1a durch Kondensation mit Dichlormethoxyphosphan erhalten. Mit 1H-NMR-Untersuchungen konnte gezeigt werden, daß die Nucleobasen eine andere Konformation als im (2′→ 5′)- oder (3′→ 4′)ApA einnehmen. Aus thermodynamischen Parametern sowie der Hypochromizität ergibt sich für 3e eine größere Basenwechselwirkung als für 2e. Einzelstrang-spezifische Nuclease S1 spaltet 2e deutlich schneller als (3′→ 5′)ApA und reagiert damit empfindlich auf die Aglyconmodifikation. Die Kondensation des 5′-entschützten Dimers 3b mit dem Monomer 1c, gefolgt von der Abspaltung der Schutzgruppen, führt zu (2′→ 5′)-TupTupTu (4e). Dies stellt ein Analogon von (2′→ 5′)ApApA dar, das als Triphosphat antiviral wirksam ist.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198419840407
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    Chemie und Stereochemie der Iridoide, IV. Synthese und Röntgenstrukturanalyse von 15-Methyl-12-epi-prostaglandin F2β (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 761-772 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry and Stereochemistry of Iridoids, IV. - Synthesis and X-Ray Structure Analysis of 15-Methyl-12-epi-prostaglandin F2βCrystalline(15R)- and (15S)-15-methyl-12-epi-PGF2β [15R)-5b and 5b] are synthesized enantiomerically pure starting from (1S,6R,9R)-(+)-7,9-bis(p-phenylbenzoyloxy)-3-oxabicyclo- [4.3.0]nonan-2-ol (1), which is prepared from catalpol. Contrary to our described synthesis of 12-epi-PGF2β, the intermediate products 2-5a are crystalline by virtue of the introduction of the p-phenylbenzoyl protecting group. Thus, their physical constants could be determined unequivocally. The X-ray structure analysis of (15R)-15-epi-PGF2β proves the correctness of our earlier statements based on analytical and spectroscopical investigations.
    Notes: Ausgehend von dem aus Catalpol hergestellten (1S,6R,7R,9R)-(+)-7,9-Bis(p-phenylbenzoyloxy)-3-oxabicyclo[4.3.0]nonan-2-ol (1) werden (15R)- und (15S)-15-Methyl-12-epi-PGF2β [(15R)-5b und 5b] kristallin und enantiomerenrein synthetisiert. Im Gegensatz zu der von uns beschriebenen Synthese von 12-epi-PGF2β sind durch die Einführung der p-Phenylbenzoyl-Schutzgruppen auch die Zwischenprodukte 2-5a kristallin, so daß ihre physikalischen Konstanten eindeutig bestimmt werden konnten. Die Röntgenstrukturanalyse von (15R)-15-Methyl-12-epi-PGF2β beweist, daß die von uns aus den analytischen und spektroskopischen Untersuchungen gemachten Aussagen richtig sind.
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    URL: http://dx.doi.org/10.1002/jlac.198419840412
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    5,10-Überbrückte Pyrido [3,2-g]chinoline durch [4 + 2]-Cycloaddition von Dienophilen an Pyrido[3,2-g]chinoline (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 877-887 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 5,10-Bridged Pyrido[3,2-g]quinolines via [4+2] Cycloaddition of Dienophiles to Pyrido[3,2-g]quinolinesIn a Diels-Alder reaction, (E)-1,2-dichloroethene (5a), α-acetoxyacrylonitrile (5b), and maleic anhydride (8), respectively, add to the medium ring of some pyrido[3,2-g]quinolines to afford the 5,10-bridged pyrido[3,2-g]quinolines 6a - c, e, f, and 9a - c, respectively. The regioisomeric α-acetoxyacrylonitrile adducts of 4b arise in a ration of 6e:6f = 94.6. On hydrolysis of this mixture, only ketone 7 is obtained. The structures of all compounds are proven by their proton and carbon-13 spectra.
    Notes: (E)-1,2-Dichlorethen (5a), α-Acetoxyacrylnitril (5b) bzw. Maleinsäureanhydrid (8) addieren sich in einer Diels-Alder-Reaktion an den mittleren Ring einiger Pyrido[3,2-g]chinoline 4 zu den 5, 10-überbrückten Pyrido[3,2g]chinolinen 6a - c, e, f bzw. 9a - c. Die regioisomeren α-Acetoxyacrylnitril-Addukte von 4b entstehen dabei im Verhältnis 6e:6f = 94:6. Durch Hydrolyse erhält man daraus das einheitliche Keton 7. Die Strukturen aller Verbindungen wurden 1H- und 13C-NMR-spektroskopisch bewiesen.
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    Chemie reaktiver Kationen von Schwefeldioxidanalogen, X. Umsetzung mit aromatischen Carbodiimiden - Darstellung von Benzothiadiazinen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 904-910 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Reactive Cations Derived from Sulfur Dioxide Analogues, X. - Reaction with Aromatic carbodiimides - Synthesis of BenzothiadiazinesDiphenyl- and bis(4-methoxyphenyl)carbodiimide react with N-methyl-N-sulfinylmethanaminium tetrafluoroborate (2) to give benzothiadiazine 1-oxides 3. The structure of the substituted compound 3a was determined, the course of the complex reaction is discussed.
    Notes: Diphenyl- und Bis(4-methoxyphenyl)carbodiimid reagieren mit N-Methyl-N-sulfinylmethanaminium-tetrafluoroborat (2) unter Bildung von Benzothiadiazin-1-oxiden 3. Die Struktur der substituierten Verbindung 3a wurde bestimmt, der Verlauf der komplexen Reaktion wird diskutiert.
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    Synthesis of Peptides with α,β-Dehydroamino Acids, I. Synthesis of N-Benzyloxycarbonyl and N-Trifluoroacetyl Dipeptides of Dehydroalanine and Dehydrophenylalanine (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 920-928 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese von Peptiden mit α,β-Dehydroaminosäuren, I. - Synthese von N-(Benzyloxycarbonyl)-und N-(Trifluoracetyl) dipeptiden von Dehydroalanin und DehydrophenylalaninDie Kondensation von Nα-(Benzyloxycarbonyl)- und Nα-(Trifluoracetyl)aminosäureamiden mit Brenztrauben- und Phenylbrenztraubensäure in Gegenwart von p-Toluolsulfonsäure als Katalysator führt zu N-(Benzyloxycarbonyl)- und N-(Trifluoroacetyl)dehydrodipeptiden mit C-ständigem ΔAla bzw. ΔPhe (Tab 2 und 3).
    Notes: Condensation of amides of N-(benzyloxycarbonyl)- and N-(trifluoroacetyl)amino acid with pyruvic and phenylpyruvic acid yields, in the presence of p-toluenesulfonic acid as a catalyst, N-(benzyloxycarbonyl)- and N-(trifluoroacetyl)dehydro dipeptides with C-terminal Δ Ala and ΔPhe, respectively (Table 2 and 3).
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    Asymmetrische Synthesen über heterocyclische Zwischenstufen, XXIII. Studien zur enantioselektiven Synthese von α-Alkyl-α-(2-furyl)-glycinen durch Alkylieren von an C-6 chiral substituierten 3-(2-Furyl)-3,6-dihydro-2H-1,4-oxazin-2-onen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 939-950 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Synthesis via Heterocyclic Intermediates, XXIII. - Studies on the Enantioselective Synthesis of α-Alkyl-α-(2-furyl)glycines by Alkylation of 3-(2-furyl)-3,6-dihydro-2H-1,4-oxazin-2-ones chirally Substituted at C-63-(2-Furyl)-3,6-dihydro-2H-1,4-oxain-2-ones 10 and 11 are synthesized from DL-(2-furyl)glycine and 2-hydroxyalkanoic acids 4. The heterocycles 10 and 11 contain an endocyclic chiral center at C-6. Their potassium derivatives 12 (obtained with potassium tert-butoxide) react with alkyl halides R2 - X in good chemical yields and with d. e. values (d. e. = asymmetric induction) from 50 → 95% to give the adducts 13. These on hydrolysis are cleaved to yield α-alkyl-α-(2-furyl)-glycines 17 and 2-hydroxyalkanoic acids 4.
    Notes: Ausgehend von DL-(2-Furyl)glycin und den 2-Hydroxyalkansäuren 4 werden die 3-(2-Furyl)-3,6-dihydro-2H-1,4-oxazin-2-one 10 und 11 aufgebaut, die an C-6 ein endocyclisches Chiralitätszentrum besitzen. Deren Kaliumverbindungen 12 (erhalten mit Kalium-tert-butylat) reagieren mit Alkylhalogeniden R2 - X an C-3 mit guten chemischen Ausbeuten und mit 50 → 95% d.e.) (d.e. = asymmetrische Induktion). Der Alkylrest R2 tritt trans zu R1 (am induzierenden Zentrum) ein. Bei der Hydrolyse der Addukte 13 werden die 2-Hydroxyalkansäuren 4 und die (optisch aktiven) α-Alkyl-α-(2-furyl)glycine 17 freigesetzt.
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    Über die Herkunft von 3,6-Epoxyalkandisäuren im Humanurin (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1513-1518 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Origin of 3,6-Epoxyalkanedioic Acids in Human UrineThe 3,6-epoxyalkanedioic acids 1-4 recently found in human urine are obviously metabolic end products of so far unknown precursors produced in the body.
    Notes: Die im Humanurin kürzlich aufgefundenen 3,6-Epoxyalkandisäuren 1-4 sind offenbar Endabbauprodukte im Körper gebildeter bisher unbekannter Vorstufen.
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    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984) 
    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.198419840601
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  • 47
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    Metalloporphyrins in Polymeric Matrices, Micelles, and Vesicles, VI. Hydrophobic and Hydrophilic Derivatives of 3,8-Diformyl-deuteroporphyrin Dimethyl Ester and their Interaction with Vesicles (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1057-1067 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metalloporphyrine in polymeren Matrizen. Mizellen und Vesikeln, VI. - Hydrophobe und hydrophile Derivate des 3,8-Diformyldeuteroporphyrin-dimethylesters und ihre Wechselwirkung mit Vesikeln3,8-Diformyldeuteroporphyrin-dimethylester (1a) wurde durch Ozonisierung des diprotonierten Dikations von Protoporphyrin-dimethylester 1b erhalten. Mehrere Derivate wurden dargestellt, die entweder hydrophobe Eigenschaften aufweisen oder hydrophile Substituenten in der “nördlichen Hemisphäre” des Porphyrinliganden oder an beiden Seiten tragen. Die Porphyrine wurden in wäßrigen Medien gelöst, die Vesikel mit elektroneutralen, -negativen oder -positiven Oberflächenladungen enthielten. Der Aufenthaltsort der gelösten Porphyrine wurde durch den spektroskopischen Nachweis von Reaktionen der zentralen Porphyrin-Stickstoffatome oder von peripheren Substituenten mit wasserlöslichen Säuren oder Metall-Ionen bestimmt.
    Notes: 3,8-Diformyldeuteroporphyrin dimethyl ester (1a) was obtained by ozonization of the diprotonated dication of protoporphyrin dimethyl ester 1b. Several derivatives have been prepared, which are either hydrophobic, or bear hydrophilic substituents in the „northern hemisphere“ of the porphyrin ligand or on both sides. The porphyrins have then been dissolved in aqueous media containing vesicles with electroneutral, -negative, or -positive surface charges. The localization of the dissolved porphyrin chromophore was determined spectroscopically following reactions of the central porphyrin nitrogen atoms or of peripheral substituents with water-soluble acids or metal ions.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198419840602
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  • 48
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    Retinoide und Carotinoide, II Synthese von (13Z)-Retinoidsäuren (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1740-1745 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Retinoids and Carotenoids, II. - Synthesis of (13Z)-Retinoic AcidsPhosphonium ylides 3 react with (E)-2-methyl-3-(4-methyl-2-oxo-2H-pyran-6-yl)propenal (2) to give 2-pyrone derivatives 4 which undergo ring opening by treatment with sodium tetrahydroborate/potassium hydroxide/methanol affording (13Z)-retinoic acids.
    Notes: Phosphoniumylide 3 reagieren mit (E)-2-Methyl-3-(4-methyl-2-oxo-2H-pyran-6-yl)propenal (2) zu 2-Pyronderivaten 4, bei deren Reduktion mit Natrium-tetrahydroborat/Kaliumhydroxid/Methanol unter Ringöffnung (13Z)-Retinoidsäuren 5 entstehen.
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    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984) 
    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.198419841101
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  • 50
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    Pyrane, 100. 5,6-Dihydro-2H-pyran-3(4H)-on als Baustein zur Synthese pyrananellierter Heterocyclen (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1759-1777 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyrans, 100.  -  5,6-Dihydro-2H-pyran-3(4H)-one as a Building Unit for the Synthesis of Pyran-annulated Heterocyclic CompoundsOnly in a few cases 5,6-dihydro-2H-pyran-3(4H-one (3) reacts regioselectively with ortho-substituted phenylcarbonyl compounds to form pyran-annulated heterocyclic compounds like the pyrano[3,2-b]quinoline 7c. Better results are obtained in reactions involving the enamine 15d derived from 3, the silyl enol ether 18 and the lithium enolate 14 derived from 18. These pyran derivatives with 2,3- or 3,4-double bonds are well suited for successful synthesis of 2- or 4-substituted 3-pyranones such as 2, 21a, 21b, 23a-c, 26a-c, 31a-c, 32, and 35a-c. They also allow to synthesize pyrano[3,2-b]- or -[3,4-b]quinolones, -chromones, and -thiochromones 6a, 30a-c, 38a-d.
    Notes: Während 5,6-Dihydro-2H-pyran-3(4H)-on (3) sich mit ortho-substituierten Phenylcarbonylverbindungen nur in Einzelfällen regioselektiv zu pyrananellierten Heterocyclen umsetzt - z. B. zum Pyrano[2,3-b]chinolin 7c -, gelingt das besser mit dem aus 3 hergestellten Enamin 15d, dem Silylenolether 18 und dem daraus gewonnenen Lithiumenolat 14. Diese Pyranderivate mit 2,3-oder 3,4-Doppelbindungen eignen sich zur gezielten Darstellung von 2- oder 4-substituierten 3-Pyranonen - z.B. 2, 21a, 21b, 23a-c, 26a-c, 31a-c, 32, sowie 35a-c - und von Pyrano[3,2-b]- oder -[3,4-b]chinolinen, -chinolonen, -chromonen und -thiochromonen 6a, 30a-c und 38a-d.
    Additional Material: 1 Tab.
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    Synthese weiterer Eremophilan-Derivate (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1785-1790 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Further Eremophilane DerivativesStarting with suitable octalin derivatives two further eremophilane derivatives (9 and 13) isolated from Euryops species were synthesized via the epoxides 5 and 6 by regiospecific ring opening with isopropenylmagnesium bromide in the presence of copper(I) iodide followed by appropriate transformation of the eremophilanes obtained. While the preparation of the racemic ketone 9 caused no problems, the corresponding 2α-hydroxy derivative in the trans-decalin series could not be obtained in satisfactory yields. The configurations of the natural compounds have now finally been elucidated.
    Notes: Ausgehend von geeigneten Octalin-Derivaten werden zwei aus Euryops-Arten isolierte Eremophilan-Derivate (9 und 13) über die Epoxide 5 und 6 durch regiospezifische Ringöffnung mit Isopropenylmagnesiumbromid in Gegenwart von Kupfer(I)-iodid und entsprechende Umwandlung der erhaltenen Eremophilane synthetisiert. Während die Darstellung des racemischen Ketons 9 keine Probleme bereitet, konnte das entsprechende 2α-Hydroxy-Derivat in der trans-Decalin-Reihe nicht in befriedigenden Ausbeuten erhalten werden. Die Konfigurationen der Naturstoffe sind damit endgültig geklärt.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198419841104
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    Chemie der Amino-oxime, XVIII Die Cyclokondensation von (E)-β-(Chloracetylamino)propiophenon-oxim-Derivaten (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1696-1701 
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    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 Amino Oximes, XVIII. - The Cyclocondensation of (E)-β-(Chloroacetylamino)propiophenone Oxime DerivativesThe (E)-β-(chloroacetylamino)propiophenone oximes 2a-c cyclocondense by reaction with alkali to form 3,11-diphenyl-1,9-dioxa-2,6,10-14- tetraazacyclohexadeca-2,10-diene-7,15-diones 3a-c. From (E)-β-[(benzyl)(chloroacetyl)amino]propiophenone oximes 5a-c the 6-benzyl-5,6-dihydro-3-phenyl-4H- 1,2,6-oxadiazocin-7(8H)-one derivates 6a-c are formed.
    Notes: Die (E)-β-(Chloracetylamino)propiophenon-oxime 2a-c werden durch Alkali zu 3,11-Diphenyl-1,9-dioxa-2,6,10,14-tetraazacyclohexadeca-2,10-dien-7,15-dionen 3a-c cyclokondensiert. Aus (E)-β-[(Benzyl)(chloracetyl)amino]propiophenon-oximen 5a-c entstehen dagegen die 6-Benzyl-5,6-dihydro-3-phenyl-4H-1,2,6-oxadiazocin-7(8H)-on-Derivate 6a-c.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419841009
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    Enhydrazine, 37 Synthese eines Pyrazol-Analogen des 7-Aminomitosens (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1711-1718 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 37. - Synthesis of a Pyrazole Analogue of 7-AminomitoseneThe 9-step synthesis of 7-amino-10-azamitosene (2b) from 3a is described. The crystal-structure analysis of the precursor 1b of 3a secures the position of the substituted propyl group at N-1 of compounds 1 and 3-7.
    Notes: Die neunstufige Synthese von 7-Amino-10-azamitosen (2b) aus 3a wird beschrieben. Die Kristallstrukturanalyse des Vorläufers 1b von 3a sichert die Stellung des substituierten Propylrestes an N-1 der Verbindungen 1 und 3-7.
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    Synthese von 2′-Desoxyribofuranosiden des 7H-Pyrrolo[2,3-d]-pyrimidins: Einfluß des C-2-Substituenten auf die Fluoreszenz (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1719-1730 
    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 2′-Deoxyribofuranosides of 7H-Pyrrolo[2,3-d]pyrimidine: Influence of the C-2 Substituents on the Fluorescence7-Deaza-2′-deoxynebularine (2a), its 2-methylthio (2b) and 2-amino derivative (2c) have been synthesized via phase-transfer glycosylation of the nucleobases 3a, 3b, and 3c, respectively, with the 2-deoxyhalogenose 6. Glycosylation of 3a leads to the formation of a 3:1 mixture of the anomers 7a and 8a in 48-% total yield, the corresponding reaction of 3b or 3c gives mainly the β anomers in increased yield. Cleavage of the protecting groups yields 2a-c or the anomers 8a and 8c. The 2-methylthio group, as well as the 2-amino group increase the fluorescence of the parent nucleoside 2a.
    Notes: 7-Desaza-2′-desoxynebularin (2a), sein 2-Methylthio- (2b) und sein 2-Aminoderivat (2c) wurden durch Phasentransferglycosylierung der Aglycone 3a, 3b und 3c mit der Desoxyhalogenose 6 dargestellt. Die Glycosylierung von 3a führt in 48proz. Ausbeute zum 3:1-Anomerengemisch der toluoylierten Nucleoside 7a und 8a; die entsprechende Reaktion von 3b und 3c ergibt bei erhöhter Ausbeute hauptsächlich die β-Anomeren. Abspaltung der Schutzgruppen liefert 2a-c bzw. die Anomeren 8a und 8c. Sowohl die 2-Methylthiogruppe als auch der 2-Aminosubstituent verstärken die Fluoreszenz der Stammverbindung 2a.
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    Macrocyclische Trichothecene aus Baccharis coridifolia, I Miotoxin B und C, zwei neue macrocyclische Trichothecene aus Baccharis coridifolia DC (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1746-1754 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Macrocyclic Trichothecenes From Baccharis coridifolia, I. - Miotoxin B and C, two New Macrocyclic Trichothecenes From Baccharis coridifolia DCFrom extracts of the toxic Brazilian plant Baccharis coridifolia, two further macrocyclic trichothecenes were isolated. The structures of these compounds, named by us as miotoxin B and C, were elucidated by application of mass spectrometry and homo- and heteronuclear two-dimensional NMR techniques.
    Notes: Aus Extrakten der brasilianischen Giftpflanze Baccharis coridifolia wurden zwei macrocyclische Trichothecene isoliert. Die Strukturen der von uns als Miotoxin B und C bezeichneten Substanzen wurden durch Massenspektroskopie und durch homo- und heteronucleare zweidimensionale FT-NMR-Techniken aufgeklärt.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198419841015
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    Beiträge zur Chemie von Tetraketonen, III Synthese und einige Reaktionen des 1,6-Bis(p-hydroxyphenyl)-1,3,4,6-hexantetrons (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1755-1758 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Contributions to the Chemistry of Tetraketones, III. - Synthesis and Some Reactions of 1,6-Bis(p-hydroxyphenyl)-1,3,4,6-hexanetetroneCondensation of p-hydroxyacetophenone and diethyl oxalate in the presence of sodium ethoxide gave the tetraketone 3 which can be cyclized with o-phenylenediamine, hydrazine, or phenyl-hydrazine to yield the quinoxaline 1 or the 3,3′-bipyrazolyl derivatives 5 and 6, respectively. Transformation of the p-hydroxyphenyl group in compounds 1 and 3 with methyl isocyanate/triethylamine gave the corresponding carbamates 2 and 4. By condensation of 4 with hydrazine or phenylhydrazine the pyrazoles 7 and 8 were prepared. Compounds 4, 7, and 8 showed no progressive inhibitory properties against acetylcholinesterase.
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    Das Verhalten von (1α,2α,5α,6α)-3,4-Bis(trimethylsiloxy)tricyclo[4.2.1.02,5]nona-3,7-dien gegenüber Oxidationsmitteln (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1778-1784 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (1α,2α,5α,6α)-3,4-Bis(trimethylsiloxy)tricyclo[4.2.1.02,5]nona-3,7-diene on Treatment with Oxidative Reagents(1α,2α,5α,6α)-3,4-Bis(trimethylsiloxy)tricyclo[4.2.1.02,5]nona-3,7-diene (1) is treated with different oxidative reagents. The reaction with halogens (Br2, Cl2) primarily yields the cyclobutanedione 2 which adds a second mole of halogen at the olefinic double bond. The adduct 3 is stabilized by forming 4a with an intramolecular ether bridge. Addition of chlorine to 2 directly yields 4b.  -  Reaction of 1 with DMSO/Ac2O or Cu(II) acetate in acetic acid causes an oxidative dimerization to yield 5 or 6, respectively. In the case of Cu(II) acetate the anhydride 7 is obtained as a second product.
    Notes: (1α,2α,5α,6α)-3,4-Bis(trimethylsiloxy)tricyclo[4.2.1.02,5]nona-3,7-dien (1) wird mit verschiedenen Oxidationsmitteln behandelt. Die Reaktion mit Halogenen (Br2, Cl2) liefert zunächst das Cyclobutandion 2, das ein weiteres Mol Halogen an die olefinische Doppelbindung addiert. Das Dihalogenaddukt 3 stabilisiert sich durch Ausbildung einer intramolekularen Etherbrücke zu 4a. Addition von Chlor an 2 liefert unmittelbar 4b.  -  Durch Umsetzung von 1 mit DMSO/Ac2O oder mit Cu(II)-acetat/Eisessig findet eine oxidative Dimerisation zu 5 bzw. 6 statt. Im Falle der Oxidation mit Cu(II)-acetat wird als Nebenreaktion eine Ringerweiterung zum Anhydrid 7 beobachtet.
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    Zur Selbstkondensation von (β-Alkoxycarbonylalkyliden)-ammoniumsalzen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 394-402 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Self-condensation of (β-Alkoxycarbonylalkylidene)ammonium SaltsIminium chlorides or trifluoroacetates of type 2, formed by protonation of β-(alkoxycarbonyl)-enamines 1, have been proved to undergo condensation to give derivatives of 4-alkyl-2-amino-6-hydroxybenzoic acid 6 via elimination of ammonium salt and alcohol. The structures of 6 had been established by spectroscopic data as well as by further reactions. The range of application of this condensation reaction has been studied and the mechanism is discussed. In the primary step presumably a nucleophilic attack on the alkoxycarbonyl group of the iminium salt 2 takes place by the enamine 1 present in the equilibrium. Analogous reactions are also found for homologues of the enamine 1 (e.g. 11, 13 and 17) to give the condensation products 12, 14, 15, and 20.
    Notes: Durch Protonierung von β-(Alkoxycarbonyl)enaminen 1 gebildete Iminiumchloride oder -trifluoracetate 2 kondensieren unter Abspaltung von Ammoniumsalz und Alkohol zu Derivaten der 4-Alkyl-2-amino-6-hydroxybenzoesäure 6, deren Strukturen spektroskopisch und durch Umsetzungen gesichert werden. Die Anwendungsbreite der Reaktion wird ermittelt und ihr Mechanismus diskutiert. Vermutlich wird primär das Iminiumsalz 2 von dem mit ihm im Gleichgewicht vorliegenden Enamin 1 nucleophil an der Alkoxycarbonylgruppe angegriffen. Analog reagieren auch homologe Enamine von 1, beispielsweise 11, 13 und 17 zu den Kondensationsprodukten 12, 14, 15 und 20.
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    Thermolyse ortho-chlorsubstituierter 1,2-Diarylethylendiamine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 409-415 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of ortho-Chloro-Substituted 1,2-DiarylethylenediaminesOn heating bis(2,6-dichlorophenyl)ethylenediamines 1a - d give indoles and  -  in the case of the racemates 1b and d  -  tetrahydroindoloindoles. The d,1-form of the corresponding 2,4-dichloro compound 1f leads to a 2,4,5-triarylimidazolidine, the meso-form 1e to an aziridine, whose formation via a 2,cis-4,5-triarylimidazolidine appears likely from mechanistic considerations.
    Notes: Die Bis(2,6-dichlorphenyl)ethylendiamine 1a - d reagieren bei der Thermolyse zu Indolen und im Falle der Racemate 1b und d auch zu Tetrahydroindoloindolen. Die d,1-Form der entsprechenden 2,4-Dichlorverbindung 1f führt zu einem 2,4,5-Triarylimidazolidin, die meso-Form 1e zu einem Aziridin, dessen Bildung über ein 2,cis-4,5-Triarylimidazolidin durch mechanistische Betrachtungen wahrscheinlich gemacht werden konnte.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198019800309
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    Ligandstruktur und Komplexierung, LIII. Nichtcyclische Neutralliganden mit zwei zentralen Pyridin-Einheiten und starren Donorendgruppen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 512-517 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, LIII1).  -  Non-cyclic Neutral Ligands with Two Central Pyridine Units and Rigid Donor End GroupsThe synthesis and properties of the title compounds, which are rendered comparatively rigid by the two pyridine rings, are described. Their complexation with alkali, alkaline earth and transition metal ions is examined. The crystalline complexes often contain stoichiometric amounts of water. 1H-NMR spectra show that helical ligand conformations are present in solutions of the complexes.  -  Neutral molecules like urea and thiourea are also shown to form stoichiometric complexes with the new ligands.
    Notes: Synthese und Eigenschaften der durch zwei Pyridinringe versteiften Titelverbindungen werden beschrieben. Ihre Komplexierung mit Alkali-, Erdalkali- und übergangsmetallionen wird unter-sucht. Die kristallinen Komplexe enthalten häufig stöchiometrische Mengen Wasser. Die 1H-NMR-Spektren zeigen, daß in Lösungen der Komplexe helikal gewundene Ligandkonformationen vorliegen.  -  Mit Neutralmolekülen wie Harnstoff und Thioharnstoff wurden gleichfalls stöchiometrische Komplexe isoliert.
    Additional Material: 2 Tab.
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    Biologisch aktive Glykoside aus Asteroidea, I. Strukturen eines neuen Cerebrosidgemischs und von Nucleosiden aus dem Seestern Acanthaster planci (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 653-668 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Biologically Active Glycosides from Asteroidea, I1).  -  Structures of a New Cerebroside Mixture and of Two Nucleosides from the Starfish Acanthaster planciFrom the starfish Acanthaster planci the new cerebroside mixture 1 (11.7 mg per individual of average weight 150 g) and the two nucleosides 2 (2.4 mg per individual) and 3 (1.1 mg per individual) have been isolated. Acid catalyzed methanolysis of 1 afforded the methyl esters of four α-hydroxy fatty acids [tetracosanoate (major component), tricosanoate, docosanoate, and nonadecanoate], two 2-amino-1,3,4-alkanetriols [heptadecanetriol (major component) and octadecanetriol], and methyl glucoside. The nucleosides 2 and 3 have been identified as thymine deoxyribonucleoside and uracil deoxyribonucleoside, respectively. Apart from conventional analytical methods, field desorption mass spectrometry (FD-MS) was successfully used for the first time for the determination and confirmation of the structures of naturally occurring glycolipids and nucleosides.
    Notes: Aus dem Seestern Acanthaster planci wurden das neue Cerebrosidgemisch 1 (11.7 mg pro Individuum bei einem mittleren Körpergewicht von 150 g) sowie die beiden Nucleoside 2 (2.4 mg pro Individuum) und 3 (1.1 mg pro Individuum) isoliert. Die säurekatalysierte Methanolyse von 1 ergab die Methylester von vier α-Hydroxyfettsäuren [Tetracosanoat (Hauptbestandteil), Tricosanoat, Docosanoat und Nonadecanoat] zwei 2-Amino-1,3,4-alkantriole [Heptadecantriol (Hauptbestandteil) und Octadecantriol] sowie Methylglucosid. Die Nucleoside 2 und 3 wurden als Thymindesoxyribonucleosid bzw. Uracildesoxyribonucleosid identifiziert. Neben den konventionellen analytischen Methoden wurde erstmals die Felddesorption-Massenspektrometrie (FD-MS) für die Bestimmung und Absicherung der Struktur natürlich vorkommender Glykolipide und Nucleoside erfolgreich eingesetzt.
    Additional Material: 8 Ill.
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    Cycloadditionen von α-Chloralkylidenamin-oxiden an Hetero-ene, I; Carbonylverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 686-692 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of α-Chloroalkylideneamine Oxides with Hetero-enes, I; Carbonyl CompoundsCycloaddition reaction of N-(2-chloroethylidene)cyclohexylamine oxide (2) with the hetero-enes 1a - 1f at 10°C in the presence of AgBF4 in 1,2-dichloroethane as solvent furnishes the reactive, dipolar intermediate iminium salts 3a - 3f. Subsequent reduction of 3a - 3f in water by NaBH4 yields the substituted 1,3-dioxa-4-azacyclohexanes 4a - 4f. From the bicyclic “hetero-ene” camphor (5) and from cholestanone (8) the spirocyclic compounds 7 and 9 have been obtained in an analogous way.  -  On the other hand, reaction of the hetero-enes 1c, 1e, 1f, and cyclododecanone (11) with 2 in the presence of AgBF4 give the iminium salts 3c, 3e, 3f and 12 which, in aquous 10% KCN solution, yield the nitriles 10a - 10c and 13 as mixtures of their isomers.
    Notes: Durch Cycloaddition des aus N-(2-Chlorethyliden)cyclohexylamin-oxid (2) in Gegenwart von AgBF4 in 1,2-Dichlorethan bei -10°C entstehenden reaktiven dipolaren Zwischenprodukts an die Hetero-ene 1a - 1f sowie anschließende reduktive Behandlung der Iminiumsalze 3a - 3f mit NaBH4 in Wasser entstehen die substituierten 1,3-Dioxa-4-azacyclohexane 4a - 4f; aus dem bi-cyclischen “Hetero-en” Campher (5) und aus Cholestanon (8) werden in analoger Weise die spiro-cyclischen Verbindungen 7 bzw. 9 erhalten.  -  Andererseits werden aus 1c, 1e, 1f sowie aus Cyclododecanon (11) mit 2 in Gegenwart von AgBF4 und anschließender Reaktion der Iminiumsalze 3c, 3e, 3f bzw. 12 mit 10proz. wäßriger KCN-Lösung die Nitrile 10a - 10c sowie 13 als Isomerengemische synthetisiert.
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    Synthese heteroaromatisch substituierter Harnstoffe und Chlorformamidine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 693-698 
    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 Heteroaromatic Substituted Ureas and ChloroformamidinesCurtius degradation of heteroaromatic carbonyl azides leads to isocyanates, which react with amines to give the trisubstituted ureas 1. Some of these can be converted into the corresponding chloroformamidines 2 by chlorination with CCl4/(C6H5)3P.
    Notes: Der Curtius-Abbau heteroaromatischer Carbonsäureazide führt zu Isocyanaten, die mit sekundären Aminen zu den trisubstituierten Harnstoffen 1 reagieren. Einige dieser Harnstoffe können durch Chlorierung mit CCl4/(C6H5)3P in die entsprechenden Chlorformamidine 2 übergeführt werden.
    Additional Material: 2 Tab.
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    Herstellung bi- und tricyclischer Pyrrol-SystemeHerrn Prof. Dr. Dr. h. c. R. Huisgen in freundschaftlicher Verbundenheit zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 703-714 
    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 Bi- and Tricyclic PyrrolesHerrn Prof. Dr. Dr. h. c. R. Huisgen in freundschaftlicher Verbundenheit zum 60. Geburtstag gewidmet.Phthalimidoalkane-1,4-diones smoothly react with aromatic and aliphatic amines to give the substituted (phthalimidoalkyl)pyrroles 1 - 16. Hydrazinolysis of these compounds yields tricyclic 4H-pyrrolo[1,2-a][1,4]benzodiazepines 17 - 23 and bicyclic pyrrolo[1,2-c]imidazoles 24, 25, pyrrolo[1,2-c]pyrimidines 26, 27, pyrrolo[1,2-a]pyrazines 28 - 30, and pyrrolo[2,1-d][1,4]diazepines 31, 32, respectively.
    Notes: Phthalimidoalkan-1,4-dione lassen sich leicht mit aromatischen und aliphatischen Aminen zu substituierten (Phthalimidoalkyl)pyrrolen 1 - 16 umsetzen; die anschließende Hydrazinolyse der Produkte liefert die tricyclischen 4H-Pyrrolo[1,2-a][1,4]benzodiazepine 17 - 23 bzw. die bicyclischen Pyrrolo[1,2-c]imidazole 24, 25, Pyrrolo[1,2-c]pyrimidine 26, 27, Pyrrolo[1,2-a]pyrazine 28 - 30 und Pyrrolo[2,1-d][1,4]diazepine 31, 32.
    Additional Material: 3 Tab.
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    Additionen von Organozink verbindungen an C = C-Bindungen, III. Anlagerung von Bis(2-methylallyl)zink an para - an meta substituierte Styrole (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 736-743 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Organozinc Compounds to C = C-Bonds, III1).  -  Addition of Bis(2-methylallyl)zinc to para- and meta-Substituted StyrenesA Hammett correlation between the ratio of M → Cprim/M → Csec addition and the substituent constants s̰+ has been found for the addition of bis(2-methylallyl)zinc (1) to p- and m-substituted styrenes 2 - 8. Electron donating substituents favour M → Cprim addition, electron withdrawing substituents M → Csec addition.
    Notes: Für die Addition von Bis(2-methylallyl)zink (1) an p- und m-substituierte Styrole 2 - 8 wurde eine Hammett-Beziehung zwischen dem Verhältnis von M → Cprim/M → Csek-Addition und den Substituentenkonstanten s̰+ gefunden. Elektronenabgebende Substituenten begünstigen die M → Cprim-Addition, elektronenanziehende Substituenten die M → Csek-Addition.
    Additional Material: 2 Ill.
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    Reaktionen von Nickelocen mit Organomagnesiumverbindungen und Bildung von η3-Allyl-η5-cyclopentadienylnickel-Komplexen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 744-753 
    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 Nickelocene with Organomagnesium Halides and Preparation of η3-Allyl-η5-cyclopentadienylnickel ComplexesNickelocene (1) reacts in ether/THF (ca. 5:1) with the 2-alkenylmagnesium compounds 2 - 5 and 11 in a molar ratio Ni/Mg - R = 1 to give the η3-allyl-η5-cyclopentadienylnickel complexes 6 - 9 and 12. Analogous compounds 14 - 19 are formed by the reaction of isopropyl- or isobutylmagnesium halide and 1,3-dienes with 1. Mixtures of isomeric allyl complexes are formed in the reaction of unsymmetrically substituted 1,3-dienes. The mixtures of syn-anti isomers equilibrate at 90°C. At 120°C an equilibration between the allylic isomers occurs.
    Notes: Nickelocen (1) reagiert in Ether/THF (ca. 5:1) mit den 2-Alkenylmagnesiumverbindungen 2 - 5 und 11 im Molverhältnis Ni/Mg - R = 1 glatt zu den η3-Allyl-η5-cyclopentadienylnickel-Komplexen 6 - 9 und 12. Analoge Verbindungen 14 - 19 entstehen bei gleichzeitiger Einwirkung von Isopropyl- oder Isobutylmagnesiumhalogeniden und 1,3-Dien auf 1. Mit unsymmetrisch substituierten 1,3-Dienen entstehen Mischungen isomerer Allylkomplexe, die beim Erhitzen auf 90°C in Gleichgewichtsgemische der syn-anti-Isomeren und bei 120°C in solche der Allyl-Isomeren übergehen.
    Additional Material: 7 Tab.
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    1,2-Naphthochinon-Derivate aus Kulturen des Mycosymbionten der Flechte Trypethelium eluteriae (Trypetheliaceae) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 779-785 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,2-Naphthochinon-Derivate from Cultures of the Mycosymbiont from the Lichen Trypethelium eluteriae (Trypetheliaceae)From cultures of the mycosymbiont of the tropical cortical lichen Trypethelium eluteriae Sprengel the antibiotically active 1,2-naphthoquinones trypethelone (2), trypethelone methyl ether (3), 8-methoxytrypethelone methyl ether (5), and 4′-hydroxy-8-methoxytrypethelone methyl ether (6) have been isolated. The substitution pattern of these new derivatives of (+)-dunnione (1) is in accord with a polyketide biogenesis of the quinone system.
    Notes: Aus Kulturen des Mycosymbionten der tropischen Rindenflechte Trypethelium eluteriae Sprengel wurden die antibiotisch aktiven 1,2-Naphthochinone Trypethelon (2), Trypethelon-methylether (3), 8-Methoxytrypethelon-methylether (5) und 4′-Hydroxy-8-methoxytrypethelon-methylether (6) isoliert. Es handelt sich um Derivate des (+)-Dunnions (1), deren Substituentenanordnung mit einer Polyketidbiogenese des Chinonsystems im Einklang ist.
    Additional Material: 2 Ill.
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    Synthesis of Isomeric N-Benzyl Derivatives of 1,2-Propanediamine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 786-790 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese isomerer N-Benzylderivate des 1,2-PropandiaminsBenzaldehyd reagiert mit der 1-Aminogruppe des 1,2-Propandiamins viel leichter zur Schiffschen Base als mit der 2-Aminofunktion. Dieser Unterschied ermöglicht die Synthese aller isomeren Mono-sowie Dibenzylderivate von racemischem und chiralem 1,2-Propandiamin (Schema 1, Tabelle 1).
    Notes: Benzaldehyde reacts with the 1-amino group of 1,2-propanediamine (1) to give a Schiff base much more readily than with the 2-amino group. This difference permits synthesis of all the isomeric mono- and dibenzyl derivatives of racemic and chiral 1,2-propanediamine (Table 1, Scheme 1).
    Additional Material: 1 Ill.
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    Oxidative Umlagerung von α-Benzylidenketonen mit Thallium(III)-nitrat in Methanol (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1283-1295 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Rearrangement of α-Benzylideneketones with Thallium(III) Nitrate in MethanolSterically unhindered arylidene- and diarylideneacetones 1 or 2 having electron releasing aryl groups yielded with thallium(III) nitrate in methanol β-ketoacetals 3, 4 and 5, respectively. Electronegatively substituted 1f and sterically hindered 1g and 1h gave the 4-arylcrotonic esters 7 and by-products, while 1,3-dibenzylidenacetone (2a) yielded besides the expected products also the branched acetal esters 13a and 13b. Formation of the anomalous products 7 and 13 can be rationalized assuming a common cyclopropanone type intermediate.
    Notes: Sterisch unbehinderte Aryliden- und Diarylidenacetone 1 bzw. 2 mit elektronenspendenden Aryl-gruppen liefern mit Thallium(III)-nitrat in Methanol die β-Ketoacetale 3, 4 bzw. 5. Das elektronegativ substituierte 1f sowie die sterisch gehinderten Acetonderivate 1g und 1h ergeben die 4-Arylcrotonsäureester 7 und Nebenprodukte, während aus 1,3-Dibenzylidenaceton (2a) neben den erwarteten Produkten auch die verzweigten Acetalester 13a und 13b entstehen. Für die Bildung der anomalen Produkte 7 und 13 wird als gemeinsames Zwischenprodukt ein Cyclopropanonderivat vorgeschlagen.
    Additional Material: 1 Tab.
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980) 
    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.198019800901
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    Dimere Naphthochinone, IV. Synthese von Biramentaceon, Mamegakinon und Rotundichinon (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1321-1347 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimeric Naphthoquinones, IV1).  -  Synthesis of Biramentaceone, Mamegakinone and RotundiquinoneMamegakinone (8a), biramentaceone (12a), 3,3′-bijuglone (8b), 2,2′-bijuglone (12b) and their methyl ethers were prepared by oxidative coupling of substituted 4-methoxy-1-naphthols; indigoids like 24 are intermediates. Cooxidation of the isomeric dimethoxy-1-naphthols 4a, 9a and 4b, 9b yields rotundiquinone dimethyl ether (29c) and 2,3-bijuglone dimethyl ether (29d) in the same manner.  -  Characters and spectra of the compounds are discussed.
    Notes: Mamegakinon (8a), Biramentaceon (12a), 3,3′-Bijuglon (8b) und 2,2′-Bijuglon (12b) sowie deren Methylether wurden durch Phenoloxidation geeignet substituierter 4-Methoxy-1-naphthole über indigoide Zwischenstufen vom Typ 24 synthetisiert. Die Cooxidation der isomeren Dimethoxy-1-naphthole 4a, 9a bzw. 4b, 9b lieferte analog Rotundichinon-dimethylether (29c) und 2,3-Bijuglon-dimethylether (29d).  -  Eigenschaften und Spektren der Verbindungen werden diskutiert.
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    (Cycloalkylmethyl)bis(η5-cyclopentadienyl)titan(III)-Komplexe (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1361-1370 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Cycloalkylmethyl)bis(η5-cyclopentadienyl)titanium(III) ComplexesReaction of bis(cyclopentadienyl)titanium dichloride (1) and isopropylmagnesium bromide (2) with the methylenecycloalkanes 3-8 (cyclopropane), 35 (cyclobutane), and 37 (cyclopentane) leads to the (cycloalkylmethyl)bis(cyclopentadienyl)titanium(III) compounds 9-14, 36, and 38. The cyclopropylmethyl complexes 12-14, which have at least two geminal methyl substituents, are stable. Compounds 9-11, 36, and 38, in which appropriate substituents are lacking, rearrange by ring opening followed by C = C bond isomerization to give the (η3-allyl)bis(η5-cyclopentadienyl)titanium complexes 23-26 and 40.
    Notes: Bei der Reaktion von Bis(cyclopentadienyl)titandichlorid (1) und Isopropylmagnesiumbromid (2) mit den Methylencycloalkanen 3-8 (Cyclopropan), 35 (Cyclobutan) und 37 (Cyclopentan) entstehen die (Cycloalkylmethyl)bis(cyclopentadienyl)titan(III)-Verbindungen 9-14, 36 und 38. Bei mindestens einer geminalen Dimethylsubstitution sind die Cyclopropylmethyl-Komplexe 12-14 stabil. Bei fehlender oder ungeeigneter Substitution lagern sich die Verbindungen 9-11, 36 und 38 durch Ringöffnung und anschließende C = C-Bindungsisomerisierung in die (η3-Allyl)bis(η5-cyclopentadienyl)titan-Komplexe 23-26 und 40 um.
    Additional Material: 2 Tab.
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    Synthesen mit α-metallierten Isocyaniden, XLIII.Versuche mit lithiierten α,ω-Alkylendiisocyaniden (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 28-36 
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    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, XLIII1).  -  Experiments with Lithiated α,ω-Alkylene Diisocyanides1,2-Ethylene diisocyanide (4a) reacts with two equivalents of butyllithium (- 100°C) to give 1,1-dilithio-1,2-ethylene diisocyanide (7) which with ketones yields the oxazines 11. - 1,3-Propylene diisocyanide (4b) reacts with one equivalent butyllithium (- 70°C) to furnish 1-lithio-1,3-propylene diisocyanide (12) which cyclizes to afford 3-lithio-1-pyrrolin-3-yl isocyanide (14). With ketones, chlorotrimethylsilane, and epoxides 14 furnishes the compounds 17-19 and 21. -1,4-Butylene diisocyanide (4c) reacts (- 100°C) with one equivalent butyllithium to give 1-lithio-1,4-butylene diisocyanide (23), and with two equivalents to give 1,4-dilithio-1, 4-butylene diisocyanide (28). Both compounds are thermolabile, but can be trapped by electrophils which react below -60°C.
    Notes: 1,2-Ethylendiisocyanid (4a) reagiert mit zwei Äquivalenten Butyllithium (-100°C) zum 1,1-Dilithio-1,2-ethylendiisocyanid (7), das mit zwei Äquivalenten eines Ketons die Oxazine 11 liefert.  -  1,3-Propylendiisocyanid (4b) liefert mit einem Äquivalent Butyllithium ( - 70°C) 1-Lithio-1,3-propylendiisocyanid (12), das zum 3-Lithio-1-pyrrolin-3-ylisocyanid (14) cyclisiert, welches mit Ketonen, Chlortrimethylsilan und Epoxiden die Verbindungen 17-19 und 21 liefert.  -  1,4-Butylendiisocyanid (4c) ergibt mit einem Äquivalent Butyllithium 1-Lithio-1,4-butylendiisocyanid (23), mit zwei Åquivalenten 1,4-Dilithio-1,4-butylendiisocyanid (28) (- 100°C). Beide Lithiumverbindungen sind thermolabil, können aber mit solchen Elektrophilen abgefangen werden, die bereits unterhalb -60°C reagieren.
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    Nucleotide, XI. Synthese und Eigenschaften von Dinucleosidmonophosphaten mit Thymidin und 1-(2′-Desoxy-β-D-ribofuranosyl)lumazinen als BausteineHerrn Prof. Dr. H. Bredereck in Verehrung zum 75. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 50-64 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleotides, XI1).  -  Synthesis and Properties of Dinucleoside Monophosphates with Thymidine and 1-(2′-Deoxy-β-D-ribofuranosyl)lumazines as Building BlocksHerrn Prof. Dr. H. Bredereck in Verehrung zum 75. Geburtstag gewidmet.The synthesis of various dinucleoside monophosphates (6a-e) with thymidine (3a) and 1-(2′-deoxy-β-D-ribofuranosyl)lumazines (3b-d) as building blocks via the phosphotriester approach is described. The completely protected phosphotriesters (4a -e) as well as the partially deblocked intermediates (5a-e) have been isolated and characterized by physical methods. Intramolecular interactions in the free dinucleoside monophosphates 6a-e have been detected by the determination of the hypochromicities and measurement of CD spectra, revealing a small base-stacking effect. Enzymatic hydrolysis of the dinucleoside monophosphates with snake venom and spleen phospodiesterase strongly depends on various structural features and is greatly retarded in presence of the 6,7-diphenyllumazine moiety as an aglycone.
    Notes: Die Synthese verschiedener Dinucleosidmonophosphate (6a-e) mit Thymidin (3a) und 1-(2′-Desoxy-β-D-ribofuranosyl)lumazinen (3b-d) als Bausteine wird mit Hilfe der Phosphotriester-Methode realisiert. Die voll- (4a - e) und partiell-geschützten Phosphotriester (5a - e) werden isoliert und durch physikalische Daten charakterisiert. Intramolekulare Wechselwirkungen in den freien Dinucleosidmonophosphaten 6a-e werden durch Bestimmung der Hypochromizitäten und Aufnahme von CD-Spektren nachgewiesen und deuten auf eine schwache Basen-Stapelung hin. Enzymatische Hydrolysen dieser Dinucleosidmonophosphate mit Milz- und Schlangengift-Phosphodiesterase zeigen eine starke Strukturabhängigkeit und sind bei Gegenwart des 6,7-Diphenyllumazins als Aglykon stark verlangsamt.
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    Synthesen mit Isoxazolinen, 4. Baseninduzierte Ringöffnung von 2-Isoxazolinen; Synthese von α-Enoximen und -Enonen aus Alkenen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 80-100 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses via Isoxazolines, 41).  -  Base-initiated Ring Opening of 2-Isoxazolines; Synthesis of α-Enoximes and -Enones from Alkenes2,3)The 2-Isoxazolines 2a - e and 5 undergo ring cleavage on treatment with lithium diisopropylamide (LDA) at -78 → 0°C to afford sterically homogeneous α-enoximes 3a-e and 6. 1H- and 13C-NMR data establish that these compounds have retained the C = N-configuration of the starting isoxazoline. Subsequent deoximation by acidic TiCl3 solution in DMF yields the α-enones 4a-e and the tetrahydropyran 7, respectively. This constitutes a new, regioselective sequence (1 → 4) for the acylation of alkenes, which avoids cationic intermediates. Studies to determine the mechanistic course and the scope of the ring cleavage reaction show that endo and/or exo anions are formed first, depending on the substitution pattern. The former may isomerize (≥ -78°C) to produce enoximates; both offer the possibility to prepare new 4- or 3α-substituted isoxazolines by the reaction with electrophiles as demonstrated by two examples (2f, 2h).
    Notes: Die 2-Isoxazoline 2a -e und 5 erleiden unter der Einwirkung von Lithiumdiisopropylamid (LDA) bei - 78 → 0°C Ringöffnung zu den sterisch einheitlichen α-Enoximen 3a - e bzw. 6. Diese weisen nach 1H- und 13C-NMR-Daten die im Edukt vorgegebene C = N-Konfiguration auf. Die anschließende Desoximierung mittels saurer TiCl3-Lösung in DMF liefert die α-Enone 4a-e bzw. das Tetrahydropyran 7. Es liegt somit eine neue regioselektive Alken-Acylierungsfolge (1 → 4) vor, die unter Vermeidung kationischer Zwischenstufen verläuft. Untersuchungen zum Mechanismus und Anwendungsbereich der Ringöffnung zeigen, daß je nach Substitutionsmuster endo-und/oder exo-Isoxazolin-Anionen 10 bzw. 11 gebildet werden. Erstere können zu Enoximaten isomerisieren (≥ -78°C); beide bieten durch Umsetzung mit Elektrophilen die Möglichkeit, neue 4- oder 3α-substituierte Isoxazoline herzustellen, was an zwei Beispielen (2f, 2h) gezeigt wird.
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  • 76
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    Dimere Naphthochinone, II. Einfache und regioselektive Synthese von Naphthohydrochinon-monoalkylethern über 2,3-Dihydronaphthochinone (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 140-157 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimeric Naphthoquinones, II1) - Simple and Regioselective Synthesis of Naphthoquinol Monoalkyl Ethers via 2,3-DihydronaphthoquinonesOn catalysis of hydrogen chloride or thionyl chloride, 1,4-naphthalenediole (2 a) reacts with primary or secundary alcohols via the tautomeric 2,3-dihydronaphthoquinone (9) to give naphthoquinol monoalkyl ethers 2b - n in high yields. The influence of the substitution pattern on the regioselectivity of the reaction has been investigated.
    Notes: Naphthohydrochinon (2a) reagiert unter Katalyse von Chlorwasserstoff oder Thionylchlorid über das tautomere 2,3-Dihydronaphthochinon (9) mit primären und sekundären Alkoholen in hoher Ausbeute zu den Naphthohydrochinon-monoalkylethern 2b-n. Der Einfluß von Substituenten auf die Regioselektivität der Reaktion wird untersucht.
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    URL: http://dx.doi.org/10.1002/jlac.198019800111
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    Synthesen mit Isoxazolinen, 6. Asymmetrische Induktion bei der Reduktion von 2-Isoxazolinen zu γ-Aminoalkoholen mit zwei und drei benachbarten Stereozentren2,3) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 122-139 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses via Isoxazolines, 61). - Asymmetric Induction in the Reduction of 2-Isoxazolines to Yield γ-Amino Alcohols with Two or Three Vicinal Stereocentres2,3)The substituted 3-aminopropanols 3 and 5 with two or three adjacent chiral centres are prepared from alkenes and nitrile oxides via LiAlH4 reduction of intermediate isoxazolines 2 and 4, respectively, in a regio- and stereoselective mode. 4-Alkyl groups give rise to β-3 in ca. 40-70% stereo-selectivity. cis-4,5-Disubstitution leads to an excess of 80 - 90% of β-5, in the case of the trans-compound 4b to an excess of 45% of β-5. 1,3-Asymmetric induction here exceeds 1,2-induction, which points to Li…O complexation during the hydride-transferring step. LiAlH4 reduction of 4,5-dimethylisoxazolines 4a and 4b shows approximate additivity of substituent effects (ΔΔG
    Notes: Die substituierten 3-Aminopropanole 3 und 5 mit zwei oder drei benachbarten Chiralitätszentren werden regio- und stereoselektiv aus Alkenen und Nitriloxiden durch LiAlH4-Reduktion der Isoxazolin-Zwischenprodukte 2 bzw. 4 erhalten. 4-Alkylgruppen bewirken bei der Reduktion zu β-3 ca. 40- bis 70proz. Stereoselektivität, bei cis-4,5-Disubstitution wird ein überschuß von 80-90%, bei trans-Stellung (4b) ein solcher von ca. 45% an β-5 erhalten. Die 1,3-asymmetrische Induktion übertrifft dabei die 1,2-Induktion, was mit Li…O-Komplexierung beim Hydrid-Additionsschritt gedeutet wird. Bei der LiAlH4-Reduktion der 4,5-Dimethylisoxazoline 4a und 4b wird näherungsweise Additivität der Substituenteneffekte (ΔΔG
    Additional Material: 2 Tab.
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  • 78
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    Beiträge zur Kenntnis des chromophoren Systems der Corrine, VI. Notiz über die partielle ozonolytische Ringöffnung am Dicyano-10-bromcobinamid (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 165-167 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Knowledge of the Corrin Chromophore, VIi).  -  Note on the Partial Ozonolytic Ring Cleavage of Dicyano-10-bromocobinamideReaction of dicyano-10-bromocobinamide (1) with 1.2 equivalents of ozone at - 60°C in methanol followed by reductive work-up yields the 5,6-monoseco derivative 2.
    Notes: Die Umsetzung von Dicbano-10-bromcobinamid (1) mit 1.2 Åquivalenten Ozon bei -60°C in Methanol führt nach reduktiver Aufarbeitung zum 5,6-Monoseco-Derivat 2.
    Additional Material: 2 Tab.
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    Notiz über positionsspezifische übergangsmetallbedingte Hydridabstraktion aus Carbanionen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 171-173 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydride Eliminations, VIII1).  -  Note on Site-Specific Hydride Abstraction from CarbanionsReaction of lithium and magnesium alkyl compounds at - 20 to 0°C with ethylene in the presence of nickel chloride leads under β-hydride abstraction to completely site-specific olefin formation. In stereochemically relevant cases the formation of the thermodynamically less stable Hofmann product is slightly preferred.
    Notes: Lithium- und Magnesiumalkylverbindungen reagieren bei - 20 bis 0°C mit Ethylen in Gegenwart von Nickelchlorid unter β-Hydridabstraktion in streng positionsspezifischer Bildung zu Olefinen. In stereochemisch relevanten Füllen wird die Bildung des thermodynamisch weniger stabilen Hofmann-Produkts geringfügig bevorzugt.
    Additional Material: 1 Tab.
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    Beiträge zur Kenntnis des chromophoren Systems der Corrine, VII. Notiz über die Reaktion von Diazoessigsäure-methylester mit Lactamen; eine Modellreaktion zur Cyclisierung von 5,6-Dioxo-monosecocorrinenKorrespondenz bitte an H. H. Inhoffen, Institut für Organische Chemie der Techn. Univ., Schleinitzstraße, D-3300 Braunschweig, richten. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 168-170 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Knowledge of the Corrin Chromophore, VII1).  -  Note on the Reaction of Methyl Diazoacetate with Lactams; a Model Reaction for the Cyclisation of 5,6-DioxomonosecocorrinsThe copper-catalyzed reaction of methyl diazoacetate with the lactam 1 or the thiolactams 3 and 4 yields the O and S-alkylated products. In the case of lactam 2 the N-alkyl compound 10 is obtained.
    Notes: Die Umsetzung von Diazoessigsäure-methylester mit dem Lactam 1 oder den Thiolactamen 3 und 4 führt unter Kupferkatalyse zu O- bzw. S-alkylierten Produkten, im Falle des Lactams 2 zur N-Alkylverbindung 10.
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  • 81
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    Synthese natürlich vorkommender p-Hydroxyacetophenon-Derivate, IIIHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 185-191 
    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 Naturally Occurring p-Hydroxyacetophenone Derivatives, III Synthese natürlich vorkommender p-Hydroxyacetophenon-Derivate, IIIHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet.Starting with different p-hydroxyacetophenone derivatives ten naturally occurring compounds have been synthesized. The synthesis of the vinyl chromene 18 gave unexpected difficulties as the dehydration of the corresponding alcohol was not successful. However, the tosylhydrazone 17 afforded the desired vinyl compound.
    Notes: Ausgehend von p-Hydrogxyacetophenon-Derivaten wurden zehn natürlich vorkommende Verbindungen dargestellt. Die Synthese des Vinylchromens 18 machte unerwartete Schwierigkeiten, da die Wasserabspaltung bei dem entsprechenden Alkohol nicht gelang. Jedoch liefert das Tosylhydrazon 17 die gewünschte Vinylverbindung.
    Type of Medium: Electronic Resource
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    Studien zur β-Lactam-Synthese, VI. Austausch der Tritylthio- und der Methylthio-Gruppe in N-geschützten 2-(trans-4-Alkylthio-3-amino-2-oxo-1-azetidinyl)-acrylsäure-alkylestern2) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1527-1539 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on β-Lactam Synthesis, VI.  -  Exchange of Tritylthio and Methylthio Groups in N-Protected Alkyl 2-(trans-4-Alkylthio-3-amino-2-oxo-1-azetidinyl)acrylatesReaction of trans-3-azido- and trans-3-phthalimido-4-tritylthio-2-azetidinones 5a and 5b with silver nitrate in methanol according to the method of Lattrell yielded the silver thiolates 6a and 6b, respectively, whereas the trans-4-acylamino derivative 9a was solvolyzed to give trans-4-methyl ether 10a [presumably via oxazolineazetidinone (azetooxazolone) 30a].  -  Oxidative detritylation of 11 with iodine provided the azetidinone-4-disulfide 14. A one pot reaction of iodine/sodium p-toluenesulfinate with trityl thioethers 11 and 9a afforded the trans-4-(p-toluenesulfonylthio)-2-azetidinones 13 and 18.  -  Cleavage of methyl thioethers 20 and 27 by sulfuryl chloride and of sulfoxides 21 and 28 by thionyl chloride yielded predominantly trans-chlorides 23 and 29. The trans-3-acylamino-4-chloro-2-azetidinones 29 were cyclized to give cis-fused 4-oxa-2,6-diazabicyclo[3.2.0]hept-2-en-7-ones (azeto[3,2-d]oxazolones) 30, which react with methanol (catalyzed by tin(II) chloride) to yield trans-3-acylamino-4-methoxy-2-azetidinones 10.
    Notes: Die trans-3-Azido- und trans-3-Phthalimido-4-tritylthio-2-azetidinone 5a und 5b ergaben nach der Methode von Lattrell mit Silbernitrat in Methanol die Silberthiolate 6a und 6b, während das trans-3-Acylamino-Derivat 9a [vermutlich über das Oxazolinazetidinon (Acetooxazolon) 30a] zum trans-4-Methylether 10a solvolysierte.  -  Die oxidative Detritylierung von 11 mit Iod führte zum Azetidinon-4-disulfid 14. Mit Iod/Natrium-p-toluolsulfinat erhielt man aus den Tritylthioethern 11 und 9a im “Eintopf”-Verfahren die trans-4-(p-Toluolsulfonylthio)-2-azetidinone 13 und 18.  -  Die Spaltung der Methylthioether 20 und 27 mit Sulfurylchlorid oder der Sulfoxide 21 und 28 mit Thionylchlorid ergab überwiegend die trans-Chloride 23 bzw. 29. Die trans-3-Acyl-amino-4-chlor-2-azetidinone 29 wurden zu den cis-verknüpften 4-Oxa-2,6-diazabicyclo[3.2.0]-hept-2-en-7-onen (Azeto[3,2-d]oxazolonen) 30 cyclisiert und mit Methanol unter Zinn(II)-chlorid-Katalyse zu den trans-4-Methoxy-2-azetidinonen 10 geöffnet.
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    Über Cyanoelpasolithe AI2BIMIII(CN)6 mit AI = Tetramethyl-ammonium und das Fluorid [N(CH3)4]2CsFeF6Professor Karl Dimroth zum 70. Geburtstage am 18. August 1980 gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1549-1556 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyano Elpasolites AI2BIMIII(CN)6 with AI = Tetramethylammonium and the Fluoride [N(CH3)4]2CsFeF6Professor Karl Dimroth zum 70. Geburtstage am 18. August 1980 gewidmet.The cubic compounds [N(CH3)4]2CsM(CN)6 (MIII = Cr, Fe, Co) and the tetragonal product of fluorination, [N(CH3)4]2CsFeF6, are characterized by their X-ray powder and IR-spectroscopic data.
    Notes: Die kubischen Verbindungen [N(CH3)4]2CsM(CN)6 (MIII = Cr, Fe, Co) und das tetragonale Fluorierungsprodukt [N(CH3)4]2CsFeF6 werden röntgenographisch und IR-spektroskopisch charakterisiert.
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    Siebengliedrige Ringe durch 1,5-Cycloadditionen, VI. 7-Aminoperhydro-1,4-oxazepine und -diazepine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1573-1582 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Seven-Membered Rings by 1,5-Cycloadditions, VI1). - 7-Aminoperhydro-1,4-oxazepines and -diazepines3-Alkyl-1,3-oxazolidines 2 react with enamines 1 in the presence of trifluoroacetic acid to give 7-dialkylaminoperhydro-1,4-oxazepines 3. 1,3-Dimethyl-1,3-imidazolidine (2d) reacts with 4-(2-methyl-1-propenyl)morpholine (1a) to give 1,4,6,6-tetramethyl-7-morpholino-2,3,4,5,6,7-hexa-hydro-1 H-1,4-diazepine (3m)
    Notes: 3-Alkyl-1,3-oxazolidine 2 geben mit den Enaminen 1 in Gegenwart von Trifluoressigsäure die 7-Dialkylaminoperhydro-1,4-oxazepine 3. 1,3-Dimethyl-1,3-imidazolidin (2d) reagiert mit 4-(2-Methyl-1-propenyl)morpholin (1a) zum 1,4,6,6-Tetramethyl-7-morpholino-2,3,4,5,6,7-hexahydro-1 H-1,4-diazepin (3m).
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    3H-Selenolo[2,3-d]-1,2-thiol-3-on und 8H-Diselenolo-[3,2-b:2′,3′-e]thiopyran-8-on, zwei neue Ringsysteme (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1620-1622 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3H-Selenolo[2,3-d]-1,2-thiol-3-one and 8H-Diselenolo[3,2-b: 2′,3′-e]thiopyran-8-one, Two New Ring SystemsThe two title compounds 1 and 3a are described. They each contain a new heterocyclic ring system. The thiopyran 3a is obtained by refluxing 1 with copper powder in xylene.
    Notes: Die Titelverbindungen 1 und 3a werden beschrieben. Sie enthalten beide ein bisher unbekanntes heterocyclisches Ringsystem. Das Thiopyran 3a entsteht durch Kochen von 1 mit Kupferpulver in Xylol.
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  • 86
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    Notiz zur Reaktion von Oxepin mit Nitrosoverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1630-1631 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Note on the Reaction of Oxepin with Nitroso CompoundsOxepin (2) and p-chloronitrosobenzene (1) react to give the nitrone 3.
    Notes: Oxepin (2) gibt mit p-Chlornitrosobenzol (1) das Nitron 3.
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    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980) 
    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.198019801101
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    Synthese und NMR-Spektren von Diazadiphosphetidinen, II (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1651-1658 
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    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and NMR Spectra of Diazadiphosphetidines, II1,3,2λ5,4λ5-Diazadiphosphetidines are synthesized from PCl5 and aniline derivatives. They are partially or fully dissociated in solution to give substituted (phenylimido)phosphoric trichlorides. The dependence of the dissociation on the solvent, the temperature, and the concentration has been investigated. The reaction products of anilines and C6H5PCl4 or (C6H5)2PCl3 are exclusively monomers, i. e. they are substituted phenyl(phenylimido)phosphonic dichlorides 3 or diphenyl-(phenylimido)phosphinic chlorides 4, respectively.
    Notes: 1,3,2λ5,4λ5-Diazadiphosphetidine 1 werden aus PCl5 und Anilinderivaten synthetisiert. Sie liegen in Lösung teilweise oder ganz dissoziiert als substituierte (Phenylimido)phosphorsäuretrichloride 2 vor. Es wurde die Abhängigkeit der Dissoziation vom Lösungsmittel, der Temperatur und der Konzentration untersucht. Die Reaktionsprodukte aus Anilinen und C6H5PCl4 oder (C6H5)2PCl3 sind ausschließlich monomer, d. h. es handelt sich um substituierte Phenyl(phenylimido)phosphonsäuredichloride 3 bzw. Diphenyl(phenylimido)phosphinsäurechloride 4.
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    Reaktionen von Chlorboranen mit bifunktionellen Basen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1659-1664 
    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 Chloroboranes with Bifunctional BasesReaction of trichloroborane with 2-(trimethylsilylamino)pyridine (1b) and 2-(trimethylsilyloxy)-pyridine (2b) yields the dimeric dichloro(2-pyridylamino)borane 4 and the dimeric dichloro-(2-pyridyloxy)borane 5, respectively. In a 1:2 molar ratio tetrachlorodiborane(4) and 2b react to form the bicyclus 6, while equimolar amounts react in a complex way.
    Notes: Aus Trichlorboran erhält man mit 2-(Trimethylsilylamino)pyridin (1b) und 2-(Trimethylsilyloxy)-pyridin (2b) das dimere Dichlor(2-pyridylamino)boran 4 bzw. das dimere Dichlor(2-pyridyloxy)-boran 5. Tetrachlordiboran(4) und 2b setzen sich bei einem Molverhältnis von 1:2 zum Bicyclus 6 um, während äquimolare Mengen unübersichtlich reagieren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801104
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  • 90
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    Nucleophile Substitution an Tricyclo[4.4.1.01,6]undec-3-en-11-diazonium-Ionen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1689-1698 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleophilic Substitution at Tricyclo[4.4.1.01,6]undec-3-ene-11-diazonium IonsThe nitrous acid deamination of tricyclo[4.4.1.01,6]undec-3-en-11-ylamines 14 and 16 in the presence of sodium bromide afforded the tricyclic bromides 18 and 19 with 〉 99% retention. Configurations were assigned by chemical correlation via the carboxylic acids 13 and 15. Deuterium incorporation in D2O indicated some epimerization of the diazonium ions at higher concentrations of sodium bromide, leading to a decrease in stereospecificity. The retention of configuration observed in this study is attributed to the intervention of partially opened cyclopropyl cations.
    Notes: Die Desaminierung der Tricyclo[4.4.1.01,6]undec-3-en-11-ylamine 14 und 16 mit salpetriger Säure in Gegenwart von Natriumbromid ergab die tricyclischen Bromide 18 und 19 mit 〉 99% Konfigurationserhaltung. Die Konfigurationszuordnung erfolgte durch chemische Korrelation über die Carbonsäuren 13 und 15. Deuterium-Einbau in D2O zeigte eine geringe Epimerisierung der Diazonium-Ionen bei höheren Natriumbromid-Konzentrationen an, die zu verminderter Stereospezifität führt. Die beobachtete Konfigurationserhaltung wird mit dem Auftreten teilgeöffneter Cyclopropylkationen erklärt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198019801107
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  • 91
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    Zur Struktur rhodiumhaltiger Corrinoide (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1699-1710 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of Rhodium Containing CorrinoidsReaction of hydrogenobyrinic acid a,c-diamide (1) with [Rh(CO)2Cl]2 in glacial acetic acid/ethanol (1:1; vol.: vol.) yields rhodibyrinic acid a,c-diamide 2 as the main product. The structure of 2 is confirmed by X-ray analysis. Esterification of 2 with methanol/sulfuric acid leads to rhodibyrinic acid pentamethyl ester a,c-diamide 3a and to small amounts of its 8- and 13-epimers. Their configurations are established by CD, 1H- and 13C-NMR spectroscopy.
    Notes: Durch Umsetzung von Hydrogenobyrinsäure-a,c-diamid (1) mit [Rh(CO)2Cl]2 in Eisessig/Ethanol (1:1; Vol.: Vol.) erhält man als Hauptprodukt Rhodibyrinsäure-a,c-diamid 2. Die Identität von 2 wird durch Röntgenstrukturanalyse bestätigt. Veresterung von 2 mit Methanol/Schwefelsäure führt neben Rhodibyrinsäure-pentamethylester-a,c-diamid 3a zu den entsprechenden 8- und 13-Epimeren. Deren Konfiguration wird durch CD, 1H- und 13C-NMR-Spektroskopie gesichert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801108
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  • 92
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    Reaktionsfähigkeit von Trimethylsilylierungsreagentien (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1718-1721 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Trimethylsilylation ReagentsThe reactivity of various trimethylsilylation reagents 1 on cyclopentanone (2a) and diisopropyl ketone (2b) has been investigated. Silylation potentials of the reagents 1 are reported.
    Notes: Es wird die Reaktionsfähigkeit einiger Trimethylsilylierungsreagentien 1 gegenüber Cyclopentanon (2a) und Diisopropylketon (2b) untersucht. Silylierungspotentiale der Reagentien 1 werden angegeben.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801110
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  • 93
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    Konfiguration von 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbuttersäure, der N-terminalen Aminosäure der Nikkomycine (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1728-1735 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Configuration of 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutyric Acid, the N-Terminal Amino Acid of the NikkomycinsThe N-ethylthio(thiocarbonyl)derivative 2 of the N-terminal amino acid 1 of the nikkomycin antibiotics shows a positive Cotton effect in its circular dichroism spectrum and therefore 1 is assigned to the L-series. The relative configuration of the C atoms 3 and 4 was ascertained by 1H-NMR investigations and crystal structure analysis. Accordingly, 1 is assigned the configuration 2S,3S,4S.
    Notes: Das N-Ethylthio(thiocarbonyl)derivat 2 der N-terminalen Aminosäure 1 der Nikkomycin-Antibiotika weist Circulardichroismus mit positivem Cottoneffekt auf und 1 ist daher der L-Reihe zu-zuordnen. Die relative Konfiguration an den C-Atomen 3 und 4 wurde durch 1H-NMR- und Kristallstrukturuntersuchungen bestimmt. Danach hat 1 die Konfiguration 2S,3S,4S.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jlac.198019801112
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  • 94
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    Eine neue Synthese von 3-Benzoylmethylen-2,3-dihydrofuranen1) (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1744-1750 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of 3-Benzoylmethylene-2,3-dihydrofuransThe unknown 3-benzoylmethylene-2,3-dihydrofurans 2 has been synthesized by isomerization of ditertiary diacetylenediols 1 in the presence of mercury salts. Sometimes carbocyanine type dyes 5 are formed as by-products.
    Notes: Die bisher unbekannten 3-Benzoylmethylen-2,3-dihydrofurane 2 wurden durch Isomerisierung von ditertiären Diacetylendiolen 1 in Gegenwart von Quecksilbersalzen erhalten. Als Nebenprodukte können gelegentlich Verbindungen vom Typ der Cyaninfarbstoffe 5 gebildet werden.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801114
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  • 95
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    Metallierte Stickstoffderivate der Kohlensäure, in der organischen Synthese, XV. 2-Azaallylanionen aus N-(Benzyl)imidodithiokohlensäure-, N-(Benzyl)imidomonothiokohlensäure- und N-(Benzyl)imidokohlensäure-dialkylestern als Benzylaminanion-Äquivalente (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1751-1764 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metalated Nitrogen Derivatives of Carbonic Acid in Organic Synthesis, XV. - 2-Azaallyl Anions from Dialkyl N-(Benzyl)imidodithiocarbonates, -monothiocarbonates, and -carbonates as α-Benzylamine Anion Equivalents2,3)S,S′-Dimethyl N-(benzyl)imidodithiocarbonate (4a) was deprotonated by means of potassium tert-butoxide in THF or butyllithium in THF/HMPTA/hexane to give the 2-azaallyl anion 7a Its alkylation yields mixtures of the α- and γ-substitution products 11a and 14a. In contrast, anion 7b, obtained from the S.S′-diethyl derivative 4b, is trapped by electrophiles predominantly in α-position, yielding 11b with high regioselectivity. Thus 4b constitutes a synthetic equivalent for α-metalated benzylamine 1. The less acidic O,O′- and O,S-dialkyl derivatives 5 or 6 were also deprotonated and alkylated to give only α-adducts 12 or 13 via anions 8 or 9. - Lithium diisopropylamide under kinetic control predominantly abstracts a proton from an S-methyl group of 4a. The intermediate lithium compound 21 was trapped as silane 23 (besides 14aa). - Some further deprotonation experiments were also performed with the imino compounds 11aa, 11ab, 32a, and 32b in order to explore the scope of the metalation reaction.
    Notes: N-(Benzyl)imidodithiokohlensäure-S,S′-dimethylester (4a) wurde mit Kalium-tert-butoxid (in THF) oder mit Butyllithium (in THF/HMPTA/Hexan) zum 2-Azaallylanion 7a deprotoniert. Die Alkylierung von 7a ergibt Mischungen der α- und γ-Substitutionsprodukte 11a und 14a. Das Anion 7b (erhalten aus dem S,S′-Diethylester 4b) hingegen wird durch Elektrophile mit hoher Regioselektivität in α-Stellung zu lib substituiert und ist daher als Syntheseäquivalent für ein α-Benzylaminanion 1 nutzbar. Die schwächer aciden O,O′- und O,S-Dialkylderivate 5 und 6 ließen sich ebenfalls zu 2-Azaallylanionen 8 und 9 deprotonieren. Sie werden ausschließlich zu 12 und 13 alkyliert und silyliert. - Lithiumdiisopropylamid abstrahiert in 4a unter kinetischer Kontrolle bevorzugt ein Proton aus den S-Methylgruppen; das intermediäre Lithiumchelat 21 wurde als Silan 23 (im Gemisch mit 14aa) abgefangen. - Einige weitere Metallierungsexperimente wurden mit den Iminen 11aa, 11ab, 32a und 32b ausgeführt, um die Anwendungsbreite der Reaktion abzugrenzen.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/jlac.198019801115
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    Ligandstruktur und Komplexierung, LI. Vielzähnige Neutralliganden mit variablen Hohlräumen und Pseudohohlräumen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 425-440 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ligand Structure and Complexation, LI1).  -  Multidentate Neutral Ligands with Variable Cavities and Pseudo CavitiesNew cyclic and non-cyclic neutral ligand systems have been synthesized. They contain repeating oligoethylene glycol ethers and carboxamide functions, which allow attractive interactions between single chain segments and with terminal groups. Crystalline complexes with alkali and alkaline earth metal ions have been isolated. The complexation of Na⊕ and competing cations has been studied with the aid of 23Na-NMR spectroscopy: The sodium cation can also be displaced by neutral molecules such as urea. Chiral open-chain ligands and their complexation with alkali and alkaline earth metal salts are described.
    Notes: Neue cyclische und offenkettige Neutralligandsysteme wurden dargestellt. Sie enthalten sich wiederholende Oligoethylenglykolether- und Carbonsäureamidfunktionen, die anziehende Wechselwirkungen einzelner Kettensegmente und zwischen endständigen Gruppen gestatten. Kristalline Komplexe mit Alkali- und Erdalkalimetallionen wurden dargestellt. Mit Hilfe der 23Na-NMR-Spektroskopie wurde die Komplexierung mit Na⊕ und konkurrierenden Ionen studiert: Das Natriumkation kann auch durch Neutralmoleküle wie Harnstoff verdrängt werden. Chirale offenkettige Liganden und ihre Komplexierung mit Alkali- und Erdalkalimetallsalzen werden beschrieben.
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    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800311
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  • 97
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    Reactionen mesoionischer Fünfringheterocyclen mit O-chinoiden Verbindungen, II. Ein Beitrag zum Problem der Ketentautomerie bei mesoionischen 1,3-Oxazolium-5-olaten (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1836-1849 
    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 Mesoionic Five-membered Heterocycles with o-Quinonoid Compounds, II1).  -  A Contribution to the Problem of Ketene Tautomers of 1,3-Oxazolium-5-olates1,3-Oxazolium-5-olates acylated at C-4 react with tetrachloro-o-benzoquinone (9) to give 2,3-dihydro-1,4-benzodioxin-2-ones 10 which can formally be derived from the valence tautomeric ketenes 2. There is evidence for the assumption that ketenes are not involved in these reactions as intermediates. Furthermore, the products 15a, b which probably result from [4 + 4] cycloadducts formed primarily, have been isolated. Oxazolo[3,2-a]pyridinium-2-olates 8 acylated at C-3 react with 9 to give 1:2 adducts 20.
    Notes: C-4-acylierte 1,3-Oxazolium-5-olate reagieren mit Tetrachlor-o-benzochinon (9) unter Bildung von 2,3-Dihydro-1,4-benzodioxin-2-onen 10, die sich formal von den valenztautomeren Ketenen 2 ableiten. Es wird ein Hinweis darauf erhalten, daß Ketene bei diesen Umsetzungen nicht ais Zwischenprodukte auftreten. Weiterhin werden die Produkte 15a, b isoliert, die möglicherweise aus primär gebildeten [4 + 4]-Cycloaddukten entstehen. C-3-acylierte Oxazolo[3,2-a]pyridinium-2-olate 8 liefern mit 9 die 1:2-Addukte 20.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019801121
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    Cyclisierungen zu 9,11-disubstituierten Acronycin-DerivatenHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 503-511 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclizations to 9,11-Substituted Acronycine DerivativesHerrn Prof. Dr. M. Seefelder zum 60. Geburtstag gewidmet.The following methods for the cyclization of olefinic precursors of acronycine, which give rise to derivatives of this alkaloid 4a substituted in positions 9 and 11, are reported: Lewis acid catalysed olefin aldehyde cyclization and subsequent oxidation converts 1b into 11-hydroxynoracronycine 4e, while 1f and 7a give 9-bromonoracronycine 4c. Base catalyzed cyclization of the oxoester 2 affords the 9,11-dihydroxy derivative 10, while the corresponding oxoaldehyde, obtainable by reduction of the enol lactone 3, gives the 9-hydroxyacridone 12.
    Notes: Es wird über folgende Methoden der Cyclisierung olefinischer Acronycinvorstufen zu 9- und 11-substituierten Derivaten dieses Alkaloids1) 4a berichtet: Lewissäuren-katalysierte Olefin-Aldehyd-Cylisierung führt, ausgehend von 1b, nach Oxidation zu 11-Hydroxynoracronycin 4e; aus 1f und 7a wird 9-Bromnoracronycin 4c erhalten. Basenkatalysierte Cylisierung des Oxoesters 2 ergibt das 9,11-Dihydroxyderivat 10, der durch Readuktion des Enollactons 3 gewinnbare kor-respondierende Oxoaldehyd das 9-Hydroxyacridon 12.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800404
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  • 99
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    Desaminierung von β- und γ-Aminoalkoholen (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 518-532 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Deamination of β- and γ-Amino AlcoholsNitrous acid deaminations of the β-amino alcohols 2 and 12 afford 1,2-diols as well as ketones by pinacolic rearrangement. Both types of products arise with predominant inversion of configuration. Stereochemical studies and isotopic labeling reveal that formation of the diols involves an oxygen shift, presumably via oxirane intermediates. Deamination of the γ-amino alcohol 37 induces, in part, sequential rearrangements to give products also obtained from 12, but in different proportions and enantiomeric purities. Conformational control provides a reasonable explanation of our results.
    Notes: Die Desaminierung der β-Aminoalkohole 2 und 12 mit salpetriger Säure ergibt 1,2-Diole und durch Pinakolumlagerung Ketone. Beide Produkte werden mit überwiegender Konfigurationsumkehrung gebildet. Stereochemische Untersuchungen und Isotopenmarkierungen zeigen, daß die 1,2-Diole unter Sauerstoffverschiebung entstehen, wahrscheinlich über Oxiran-Zwischen-stufen. Desaminierung des γ-Aminoalkohols 37 führt zum Teil zu Mehrfachumlagerungen, aus denen die gleichen Produkte wie aus 12 hervorgehen, jedoch in unterschiedlicher Menge und enantiomerer Reinheit. Unsere Ergebnisse lassen sich durch konformative Kontrolle plausibel deuten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198019800406
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  • 100
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    Anellierungsreaktionen von N-Heterocyclen zu kondensierten Pyridonen mit Stickstoffbrückenatom (1980)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 542-556 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Annelation Reactions of N-Heterocycles to Condensed Pyridones with Bridgehead NitrogenThe Horner-Wittig reaction of aromatic and heteroaromatic aldehydes with phosphono succinates gives the methylenesuccinates 2a - m and 4a - k in satisfactory yields. The compounds obtained have the E-configuration, as shown by 1H-NMR-spectroscopic and by chemical investigations. When heterocyclic aldehydes 3a - m having a formyl function in the α-position to a nitrogen atom are used in this reaction, pyridones 5a - m with bridgehead nitrogen can be obtained directly or via the methylene succinates.
    Notes: Die Horner-Wittig-Reaktion von aromatischen und heteroaromatischen Aldehyden mit Phosphonobernsteinsäureestern führt zu den Methylenbernsteinsäureestern 2a - m und 4a - k in befriedigenden Ausbeuten. Wie durch 1H-NMR-spektroskopische und chemische Untersuchungen gezeigt wird, haben diese Verbindungen E-Konfiguration. Setzt man die heterocyclischen Aldehyde 3a - m mit Formylgruppe in α-Stellung zu einem Stickstoffatom um, so können  -  direkt oder über die Methylenbernsteinsäureester  -  die kondensierten Pyridone 5a - m erhalten werden.
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    URL: http://dx.doi.org/10.1002/jlac.198019800408
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