ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Säurekatalysierte Umsetzungen von 2- Vinylanilin-Derivaten mit 1-Benzyl- und 1-Methylpiperidin-4-on: Eine Elegante Synthese Neuer Polycyclischer Indol-Derivate (1993)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 76 (1993), S. 1469-1475 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acid-Catalyzed Reactions of 2-Vinylaniline Derivatives with 1-Benzyl- and 1-Methylpiperidin-4-one: An Elegant Synthesis of New Polycyclic Indole DerivativesThe reaction of 2-vinylaniline derivatives with 1-benzylpiperidin-4-one or 1-methylpiperidin-4-one in toluene at temperatures between 115 and 120° with toluene-4-sulfonic acid as catalyst leads in good yields to a new class of polycyclic indole derivatives (Scheme 1, Table 1). The structure of the new diastereoisomerically pure racemic compounds 1-5 is determined by NMR-spectroscopic methods. A reaction mechanism proceeding via cyclization of enamine 9, leading to a racemic, tricyclic reactive intermediate 10, and subsequent intramolecular 1,5-dipolar cyclization as key steps in proposed for the formation of octahydropyrido[4′,3′:4]cyclobut[1,2-b]indoles 1-5. The scope and limitations of the new method are discussed (see Table 2).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19930760407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stereoselective Syntheses of Tetrahydroesterastin-β -Lactam Analogues (1994)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 77 (1994), S. 1065-1075 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A total synthesis of the optically active tetrahydroesterastin β -lactam analogue 2 using Miller's hydroxamate approach is described (Scheme 2). Significant modification of published procedures has resulted in a short and facile stereospecific preparation of the N-[(benzyloxycarbonyl)methyl]-β -lactam 17 starting from the readily available D-serine. This material served as intermediate for the preparation of a variety of N-[(benzyloxycarbonyl)methyl]tetrahydroesterastin β-lactam analogues (Scheme 5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19940770420
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Tricyclic Pyridine Derivatives with High Affinity to the Central Benzodiazepine ReceptorDedicated to Dr. O. Isler on the occasion of his 80th birthday (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 763-781 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel tricyclic heterocycles were prepared and evaluated for their affinity to the central benzodiazepine receptor. The most potent compounds with IC50's in the nanomolar range were; found among thienoquinolizines and benzo[a]quinolizines (cf. Tables 2-5). The central ring of the tricyclic ring system may be partially unsaturated (cf. Tables 2 and 4) or fully unsaturated (cf. Tables 3 and 5) without loss of the high affinity to the receptor. The position of the ester group in the pyridinone ring is crucial for good binding (cf. Tables 1 and 2). It may be replaced by a broad variety of functional groups, e.g. amides, alkyl carbamates, alkyl groups, and hydroxyalkyl groups (cf. Tables 2-5). In the benzo[a]quinolizines, shifting the halogen atom from C(10) to C(9) leads to complete loss of affinity to the benzodiazepine receptor (cf. Table 4).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Tetrahydrolipstatin: Thermal and Hydrolytic DegradationDedicated to Dr. O. Isler on the occasion of his 80th birthday (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 1022-1036 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal and hydrolytic degradation of tetrahydrolipstatin (THL, 1) was investigated. All main degradation products were isolated, characterized, and synthesized. Labile intermediates unavailable to isolation were detected and identified by GC/MS analysis of their silylated derivatives, and whenever possible, compared with independently prepared reference compounds. The identified degradation products represent at least 97% of the total degradation mixture. Two main reaction pathways arc proposed. Pharmacological data are reported for the degradation mixture and the main degradation products.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730427
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    N-Acylureas in Peptide Synthesis: An X-Ray Diffraction and IR-Absorption Study (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 626-634 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An X-ray diffraction analysts of two N-acyl derivatives of symmetrical dialkylureas, N-[Nα-(benzyloxycarbonyl)-L-valyl] -N, N′-diisopropylurea (1) and N-{Nα(tert-butyloxy)carbonyl -L-valyl}-N-N′-dicyclohexylurea (2), and one N-acyl derivative of an unsymmetrical N-N′-dialkylurea, N-[Nα-(benzyloxycarbonyl)-L-valyl] -N′-(tert-butyl)-N-ethylurea (3), has been performed. It was established that it is the least hindered O-acylisourca N-atom that attacks intramolecularly the carbonyl group of the Nα-protected amino acid activated by the unsymmetrical carbodiimide to form the major rearrangement product. The occurrence and nature of intra- and intermolecularly H—bonded forms of the N-acylureas in the crystal state were also assessed. It was also shown that soluble N-acylureas may compete with intermolecular (peptide)N—H…O=C(peptide) H-bonds in CH2Cl2.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Preparation, Characterisation, and Structure of N-Methylated Derivatives of 1,3,5-Triamino-1,3,5-trideoxy-cis-inositol: Polyalcohols with Unusual Acidity (1990)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 73 (1990), S. 97-105 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3,5-Trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (TDCI) and 1,3,5-trideoxy-1,3,5-tris(trimethylammonio)-cis-inositol (TTCI) were prepared by methylation of 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (TACI). The ability of TDCI to form both intermolecular and intramolecular H-bonds, as demonstrated by X-ray diffraction, is probably responsible for the good solubility of TDCI in almost every common solvent. TTCI was found to be a polyol of unusual high acidity (pK1 = 8.14 ± 0.02, pK2 = 13.0 ± 0.2). This phenomenon could be explained by electrostatic interactions between the charged substituents of the cyclohexane residue.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19900730110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The Reaction Mechanism of Chromanol-Ring Formation Catalyzed by tocopherol cyclase from Anabaena variabilis KÜTZING (Cyanobacteria) (1994)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 77 (1994), S. 1721-1737 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Incubation of the synthetic 18O-labelled phytyl-hydroquinone (O4-18O)-2 with the tocopherol cyclase from Anabaena variabilis KÜTZING (Cyanobacteria) in D2O furnished the doubly labelled γ-tocopherol, (2R,3S,4′R,8′R)-(1-18O,3-2H)-1. The chirality at C(3) was determined by two independent routes providing interlocking evidence that the enzyme-catalyzed ring closure proceeds by si-protonation of the double bond of 2 and concomitant re-attack of the phenolic O-atom.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19940770705
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Chromatographic resolution of chiral intermediates in β-adrenergic blocker synthesis on chiral stationary phases (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 5 (1993), S. 554-559 
    Details
    ISSN: 0899-0042
    Keywords: HPLC ; chiral stationary phases ; resolution of enantiomers ; β-adrenergic blockers ; alcohols ; acetates ; Chiralcel OB ; Chiralcel OD ; Chiralpak OT(+) ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enantiomeric purities of optically active intermediates for β-adrenergic blocking agents prepared via enzyme-assisted processes can be determined rapidly and with high accuracy using HPLC on commercially available columns with chiral supports [Chiralcel OD, OB; Chiralpak OT(+)]. The dependence of the resolution parameters on the substitution pattern of both hydroxy compounds and their esters is reported. © 1993 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chir.530050712
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Addition von α-Ketoenaminen an 2-Acetyl-p-benzochinon (1993)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 345-350 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Addition of α-Ketoenamines to 2-Acetyl-p-benzoquinoneAddition of 2-morpholino-2-cyclohex-1-en-one 2 to 2-acetyl-quinone 1 yields benzo[c][4 H]chromen-4,7,10-trion 4 which is unstable and rearranges to 5. 4 is converted to 3-(2,5-dihydroxy-phenyl)-2-morpholino-2-cyclohex-1-en-on 3 thermically and to dibenzo[b,d]furan-4-on 7 acid catalyzed. The structure of 7 is secured by independent synthesis. Dibenzo[b,d]furan-4-on 14 is the product of reaction from 2-(p-toluidino)-2-cyclohex-1-en-on 9 and 1 with benzo[c][4 H]chromen-4,7,10-trion 10 as intermediate. By proton catalysis 5-acetyl-6-hydroxy-carbazol-1-on 13 and 4-oxo-cyclohexa[c]isochinolinium hydrochlorid 15 is obtained from 10. 1 H-cyclopenta[d]furan-3-on 17 is formed by addition of 2-(p-toluidino)-2-cyclopent-1-en-on 16 to 1. It is rearranged by proton catalysis to 3-oxo-1 H-cyclopenta[c]isochinolinium salt 18. Reaction of cyclopentan-1,2-dione and 1 yields 3 aH-cyclopenta[c]isochromen-3,6,9-trion 20, rearranging to 1 H-cyclopenta[b]benzo[d]furan-3-on 21. The stereochemistry of adducts is discussed in connection with the course of the reaction, spectroscopical evidence, molecular modelling and calculation of HOMO/LUMO and AO-coefficients.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19933350407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Zwei neue Pregnanesterglykoside aus Gongronema latifolium (Asclepiadaceae) (1993)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 335 (1993), S. 532-536 
    Details
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two New Pregnan Ester Glycosides from Gongronema latifolium (Asclepiadaceae)Two so far unknown pregnan ester glycosides named 3-O-[β-D-Glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl]-11, 12-di-O-tigloyl-17β-marsdenin (1) and 3-O-[β-D-Glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-canaropyranosyl]-11, 12-di-O-tigloyl-17β-marsdenin (2) were isolated from the chloroform extract of the leaves of Gongronema latifolium Benth. et Hook. (Asclepiadaceae). Their structures have essentially been established by one- and two-dimensional NMR methods (NOE difference spectroscopy, NOESY, HH-COSY, CH-COSY, HMBC).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19933350606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...