Synthesis of new (R)-secondary carbinols with different structures via enzymatic resolution

Abstract

The present study deals with the biocatalytic enantioselective synthesis of 19 new chiral alcohols with alkyl (C(11)-C(19)) and phenyl, substituted phenyl, heteroaromatic, and naphthyl groups 4a-4z with an (R)-configuration and high enantiomeric excess (similar to 100%). The corresponding ketones 1a-1z were synthesized and then reduced with NaBH(4) to their racemic alcohols 2a-2z, which were converted into their racemic acetyl derivatives 3a-3z. Enzymes of four different types were used for the enantioselective hydrolysis of these acetyl compounds 3a-3z. The optimal reaction conditions for these four enzymes were established by investigating the enantiomeric excesses by chiral HPLC. Amano lipase from Burkholderica cepacia (Pseudomonas cepacia) AL-PS was determined as the best enzyme in this work This study presents an environmentally friendly and green chemistry method for the synthesis of these new (R)-chiral carbinols 4a-4z. (C) 2011 Elsevier Ltd. All rights reserved.