Lipase-catalyzed kinetic resolution of threo -configured 1,2-diols: a comparative study of transesterification versus hydrolysis
摘要:
The kinetic resolution of the alpha,beta-unsaturated vicinal diols 3 has been investigated by irreversible transesterification in organic media and by hydrolysis of the corresponding diacetates 6 (Scheme 1). The best results were obtained in the hydrolysis of the diacetates with the lipase CAL-B from Candida antarctica as a catalyst. (C) 1998 Elsevier Science Ltd. All rights reserved.
Lipase-catalyzed kinetic resolution of threo -configured 1,2-diols: a comparative study of transesterification versus hydrolysis
摘要:
The kinetic resolution of the alpha,beta-unsaturated vicinal diols 3 has been investigated by irreversible transesterification in organic media and by hydrolysis of the corresponding diacetates 6 (Scheme 1). The best results were obtained in the hydrolysis of the diacetates with the lipase CAL-B from Candida antarctica as a catalyst. (C) 1998 Elsevier Science Ltd. All rights reserved.
Semisynthetic Enzymes in Asymmetric Synthesis: Enantioselective Reduction of Racemic Hydroperoxides Catalyzed by Seleno-Subtilisin
作者:Dietmar Häring、Ellen Schüler、Waldemar Adam、Chantu R. Saha-Möller、Peter Schreier
DOI:10.1021/jo981665a
日期:1999.2.1
The serine protease subtilisin was chemically converted into the peroxidase-active seleno-subtilisin. This semisynthetic enzyme catalyzes the enantioselective reduction of racemic hydroperoxides in the presence of thiophenols to yield optically active hydroperoxides and alcohols on the semipreparative scale. The kinetic parameters and enantioselectivities of seleno-subtilisin-catalyzed reduction of
Horseradish Peroxidase-Catalyzed Enantioselective Reduction of Racemic Hydroperoxy Homoallylic Alcohols: A Novel Enzymatic Method for the Preparation of Optically Active, Unsaturated Diols and Hydroperoxy Alcohols
作者:Waldemar Adam、Michael Lazarus、Ute Hoch、Marion N. Korb、Chantu R. Saha-Möller、Peter Schreier
DOI:10.1021/jo980028h
日期:1998.9.1
The kinetic resolution of chiral diastereomeric hydroperoxy homoallylic alcohols 1 by horseradish peroxidase-catalyzed asymmetricreduction affords the opticallyactive (R,R) or (R,S) allylic diols 2 and (S,S) or (S,R) hydroperoxy homoallylic alcohols 1 in high enantiomeric excess (up to 99%).
The Ti-catalyzed epoxidation of opticallyactive (S,S)-hydroperoxy homoallylic alcohols 2 affords the epoxy diol (S,R,S)-4 in high diastereoselectivity (d.r. up to 95:5), while the opticallyactive hydroxy homoallylic alcohols (R,R)-3 are epoxidized by the β-hydroperoxy alcohol 5 under titanium catalysis to the corresponding epoxy (R,S,R)-diol 4 in a diastereomeric ratio up to > 99:1. This high diastereoselectivity
Horseradish peroxidase (HRP)-catalysed enantioselective reduction of racemic hydroperoxy homoallylic alcohols: a novel enzymatic method for the preparation of optically active, unsaturated diols and hydroperoxy alcohols
作者:Waldemar Adam、Ute Hoch、Hans-Ulrich Humpf、Chantu R. Saha-Möller、Peter Schreier
DOI:10.1039/cc9960002701
日期:——
The kinetic resolution of chiral diastereoisomeric hydroperoxy homoallylic alcohols by horseradish peroxidase (HRP)-catalysed asymmetric reduction affords the optically active (R,R) or (R,S) allylic diols and (S,S) or (S,R) hydroperoxy homoallylic alcohols in high enantiomeric excess (up to 99%).
Lipase-catalyzed kinetic resolution of α,β-unsaturated α′-acetoxy ketones
作者:Waldemar Adam、Marı́a Teresa Dı́az、Chantu R Saha-Möller
DOI:10.1016/s0957-4166(98)00006-8
日期:1998.3
The lipase-catalyzed kinetic resolutions of the alpha,beta-unsaturated alpha'-acetoxy ketones 3a,b have been investigated. Of the lipases examined, CAL-B from Candida antarctica (fraction B) has been shown to be an efficient biocatalyst, which may be used effectively in preparative scale reactions. (C) 1998 Elsevier Science Ltd. All rights reserved.