Practical Two‐Step Synthesis of an Enantiopure Aliphatic Terminal (<i>S</i>)‐Epoxide Based on Reduction of Haloalkanones with “Designer Cells”

Abstract

Abstract A practical biocatalytic method for the synthesis of aliphatic β‐halogenated ( S )‐alcohols as epoxide precursors by means of an enantioselective reduction of the corresponding ketones with recombinant whole cells, bearing an alcohol dehydrogenase and a glucose dehydrogenase, was developed. The biotransformations operate at high substrate concentrations of up to 208 g/L, and afford the ( S )‐β‐halohydrins with both high conversions of &gt;95 % and enantioselectivities of &gt;99 % ee . Base‐induced cyclization of the β‐halohydrin intermediates gave the desired ( S )‐epoxides in high yield and enantiomeric purity (&gt;99 % ee ).