Highly efficient double enantioselection by lipase-catalyzed transesterification of (R,S)-carboxylic acid vinyl esters with (RS)-1-phenylethanol
摘要:
Transesterification of the title compounds using lipase B from Candida antarctica in toluene afforded the corresponding esters in good to excellent diastereomeric excess. (R)-2-Phenylpropionic acid-(R)-1-phenethyl ester 4 was isolated in 45% yield and 64% de after 2.5 h, whereas (R)-2-phenylbutyric acid-(R)-1-phenethyl ester 5 was obtained in 40% yield and 56% de after 35 h. A single recrystallization from n-hexane gave 4 with 98% de. In all reactions CAL-B showed excellent enantioselectivity (E > 100) toward (RS)-1-phenylethanol and moderate enantioselectivity (E similar to 10) toward both carboxylic acid vinyl esters. (C) 1999 Elsevier Science Ltd. All rights reserved.
Oxygen and carbon-acylation of enolates by ketenes
作者:Lynn M. Bairgrie、Régis Leung-Toung、Thomas T. Tidwell
DOI:10.1016/s0040-4039(00)82014-6
日期:1988.1
Ketenes react with lithium enolates mainly by O-acylation, thus providing a convenient route to vinyl esters and their enolates.
酮基团主要通过O-酰化与烯醇化锂反应,从而为获得乙烯基酯及其烯醇化物提供了便利的途径。
Verfahren zur Herstellung von stereoisomeren Carbonsäureestern
申请人:BASF AKTIENGESELLSCHAFT
公开号:EP1031629A2
公开(公告)日:2000-08-30
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von stereoisomeren Carbonsäureestern bestehend aus einer Säure- und einer Alkohol-Komponente mit jeweils mindestens einem chiralen Zentrum, wobei mindestens ein Stereoisomer des Carbonsäureesters in einem Überschuß vorliegt, indem man einen racemischen Carbonsäureester mit einem racemischen Alkohol in Gegenwart einer Carboxylesterhydrolase (EC 3.1.1) umsetzt.
Method for kinetic resolution of racemates of alcohols or carboxylic acid esters
申请人:——
公开号:US20030003552A1
公开(公告)日:2003-01-02
The invention relates to a method of kinetic resolution of racemates of alcohols or carboxylic acid esters. Fluorine phase marking of the quicker or more slowly reacting enantiomer is obtained by lipase-catalysed reaction of racemic alcohols with fluorinated carboxylic acid esters of racemic alcohols with water. The enantiomers are then extractively separated by division between an organic and a fluorine phase.
Nucleophilic additions to ketenes by (trimethylsilyl)lithium and by enolates
作者:Leyi Gong、Regis Leung-Toung、Thomas T. Tidwell
DOI:10.1021/jo00298a047
日期:1990.5
The Use of Vinyl Esters Significantly Enhanced Enantioselectivities and Reaction Rates in Lipase-Catalyzed Resolutions of Arylaliphatic Carboxylic Acids