Reduction of Acyl Enolates of α-Substituted β-Keto Esters by Bakers' Yeast

Abstract

Enol esters of 2-substituted-3-oxoalkanoates of (Z)-configuration were reduced by bakers' yeast to chiral 2-substituted-3-hydroxyalkanoates. The syn-selectivities of this reaction increased compared with those of the reduction of the corresponding racemic keto esters. The reaction may proceed via an asymmetric hydrolysis of the enol esters, followed by the reduction of the resulting carbonyl group.