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  • 1
    Electronic Resource
    Electronic Resource
    The Formal Total Synthesis of Epothilone A (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 2817-2823 
    Details
    ISSN: 1434-193X
    Keywords: Epothilone A ; Ring-closing metathesis ; Aldol reactions ; Lactones ; Diastereoselective alkylation ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The formal total synthesis of epothilone A is described. The key steps in the synthesis of the northern hemisphere are a Z-selective ten-membered ring-closing metathesis reaction (RCM) and the diastereoselective alkylation at C8. Aldehyde 3 is formed by introduction of the thiazole moiety by a Wittig reaction and subsequent functional group transformation. An efficient route to keto acid 5 is described.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    Directed evolution of an esterase for the stereoselective resolution of a key intermediate in the synthesis of epothilones (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 58 (1998), S. 554-559 
    Details
    ISSN: 0006-3592
    Keywords: directed evolution ; esterase ; epothilon ; Pseudomonas fluorescens ; stereoselectivity ; mutator strain ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The directed evolution of an esterase from Pseudomonas fluorescens using the mutator strain Epicurian coli XL1-Red was investigated. Mutants were assayed for their ability to hydrolyze a sterically hindered 3-hydroxy ester, which can serve as a building block in the synthesis of epothilones. Screening was performed by plating esterase producing colonies derived from mutation cycles onto minimal media agar plates containing indicator substances (neutral red and crystal violet). Esterase-catalyzed hydrolysis of the 3-hydroxy ester (ethyl or glycerol ester) was detected by the formation of a red color due to a pH decrease caused by the released acid. Esterases isolated from positive clones were used in preparative biotransformations of the ethyl ester. One variant containing two mutations (A209D and L181V) stereoselectively hydrolyzed the ethyl ester resulting in 25% ee for the remaining ester. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58: 554-559, 1998.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Enzym-Feldeffekttransistoren als enantioselektive Detektoren in der Fließinjektionsanalyse (1994)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 66 (1994), S. 700-706 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330660516
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesen von (+)-Oudemansin und (+)-Epioudemansin aus enantiomerenreinen Vorstufen; absolute Konfiguration des natürlichen (-)-Oudemansins (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 791-801 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of (+)-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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840415
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  • 5
    Electronic Resource
    Electronic Resource
    Synthesen von (-)-(S)- und (+)-(R)-Goniothalamin; absolute Konfiguration des natürlichen (+)-Goniothalamins (1979)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 484-491 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of (-)-(S)- and (+)-(R)-Goniothalamin; Absolute Configuration of the Naturally Occurring (+)-Goniothalamin(-)-(S)-Goniothalamin and its naturally occurring (+)-(R)-enantiometer were synthesised from configurationally defined precursors. The absolute configurations were additionally confirmed by ozonolysis to (-)-(S)- and (+)-(R)-malic acid. The absolute configuration given for the compound in the literature is thus corrected.
    Notes: (-)-(S)-Goniothalamin und das (+)-(R)-Enantiomer wurden aus konfigurativ definierten Vorstufen synthetisiert. Die absoluten Konfigurationen wurden zusätzlich durch Ozonabbau zu (-)-(S)- und (+)-(R)-Äpfelsäure bestätigt. Die in der Literatur angegebene absolute Konfiguration des Naturstoffs wird berichtigt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197919790409
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesen und absolute Konfigurationen von (+)-(6R,2′S)-Cryptocaryalacton und (-)-(6S,2′S)-Epicryptocaryalacton (1984)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 977-981 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses und absolute Configurations of (+)-(6R,2′S)-Cryptocaryalactone and (-)-(6S,2′S)-EpicryptocaryalatoneThe naturally occurring (+)-cryptocaryalactone [(+)-4] and the (-)-epicryptocaryalactone [(-)-5] have been synthesized starting from the optically active aldehyde. 1. The absolute configuraitons of these unsaturated lactones were determined by circular dichroism measurements.
    Notes: Das natürliche (+)-Cryptocaryalacton [(+)-4] und das (-)-Epicryptocaryalation [(-)-5] wurden, ausgehend von optisch aktivem Aldehyd 1, synthetisiert. Die absoluten Konfigurationen dieser ungesättigten Lactone wurden mit Hilfe des Circulardichroismus bestimmt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198419840515
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  • 7
    Electronic Resource
    Electronic Resource
    Umsetzung des 2-Butinsäuredianions mit Aldehyden; Synthese einiger Naturstoffe mit 5,6-Dihydro-2H-pyran-2-on-Struktur (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 337-344 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of the 2-Butynoic Acid Dianion with Aldehydes; Synthesis of some Natural Products with 5,6-Dihydro-2H-pyran-2-one Structure1)The naturally occurring 5,6-dihydro-2H-pyran-2-ones 6a, 6b and 6e have been synthesised starting from the 2-butynoic acid dianion 1 and the aldehydes 2a  -  c with 5-hydroxy-2-alkynoates 4a  -  c as intermediates.
    Notes: Die natürlich vorkommenden 5,6-Dihydro-2H-pyran-2-onderivate 6a, 6b und 6e werden ausgehend von dem 2-Butinsäuredianion 1 und den Aldehyden 2a  -  c über die 5-Hydroxy-2-alkinsäureester 4a  -  c als Zwischenstufen synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780214
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  • 8
    Electronic Resource
    Electronic Resource
    Synthese von (-)(1S, 7S)-exo-Brevicomin aus (+)-(2R, 3R)-Weinsäure-diethylester (1977)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1977 (1977), S. 732-736 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of (-1S, 7S)-exo-Brevicomine starting from (+)-(2R, 3R)-Diethyl TartrateThe sex attractant 4 of western pine beetle Dendroctonus brevicomis has been synthesised in high yield in optically active form starting from (+)-(2R, 3R)-diethyl tartrate by coupling dithiane 5c with the optically active bromide 2d.
    Notes: Der Sexuallockstoff 4 des Borkenkäfers Dendroctonus brevicomis wird in guter Ausbeute in optisch aktiver Form ausgehend von (+)-(2R, 3R)-Weinsäure-diethylester über die Kupplung des Dithianderivates 5c mit dem optisch aktiven Bromid 2d synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197719770503
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