The enantioselectivity of lipase PS in chlorinated solvents increases as a function of substrate conversion
摘要:
The enantiomeric ratio E of lipase from Pseudomonas cepacia increased markedly as a function of substrate conversion in the resolution of (+/-)-6-methyl-5-hepten-2-ol (sulcatol) when methylene chloride was used as reaction medium. Such behavior was observed, even though less pronounced, also in dichloroethane. Instead, when cyclohexane and toluene were used as reaction medium or when 3-methyl-2-cyclohexen-1-ol was employed as substrate, enzyme enantioselectivity remained constant. No explanation for the phenomenon, which can have practical implications for resolutions carried out in organic solvents, has been found yet. (C) 1997 Elsevier Science Ltd.
Combination of the lipase-catalysed resolution with the Mitsunobu esterification in one pot
作者:Eero Vänttinen、Liisa T Kanerva
DOI:10.1016/0957-4166(95)00224-d
日期:1995.7
A chemo-enzymatic method for the preparation of homochiral esters of 14 secondary alcohols with 100% theoretical yields is described in one pot through two steps: the lipase-catalysed kinetic resolution followed by the Mitsunobu esterification of the free alcohol enantiomer in situ in the resolution mixture. Mathematical equations which link the enzymatic and chemical steps were derived, resulting in an enantioconvergent synthetic tool for the preparation of chiral intermediates.
Sugai, Takeshi; Ohta, Hiromichi, Agricultural and Biological Chemistry, 1990, vol. 54, # 6, p. 1577 - 1578
作者:Sugai, Takeshi、Ohta, Hiromichi
DOI:——
日期:——
Chemo-enzymatic synthesis of (R,R)-(-)-Pyrenophorin
作者:Takeshi Sugai、Osamu Katoh、Hiromichi Ohta
DOI:10.1016/0040-4020(95)00758-z
日期:1995.10
A chemo-enzymatic approach to (R,R)-(-)-pyrenophorin starting from commercially available 6-methyl-5-hepten-2-one is described. Firstly, (R)-6-methyl-5-hepten-2-ol (sulcatol) was prepared by interface-bioreactor mediated asymmetric reduction of the corresponding ketone by a yeast, Pichia farinosa IAM 4682 (51% yield, 90%e.e.). The sequential carbon-chain elongation via Horner-Emmons olefination of
The enantiomeric ratio E of lipase from Pseudomonas cepacia increased markedly as a function of substrate conversion in the resolution of (+/-)-6-methyl-5-hepten-2-ol (sulcatol) when methylene chloride was used as reaction medium. Such behavior was observed, even though less pronounced, also in dichloroethane. Instead, when cyclohexane and toluene were used as reaction medium or when 3-methyl-2-cyclohexen-1-ol was employed as substrate, enzyme enantioselectivity remained constant. No explanation for the phenomenon, which can have practical implications for resolutions carried out in organic solvents, has been found yet. (C) 1997 Elsevier Science Ltd.