Diastereoselective microbial reduction of (S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester

The chiral intermediate (1S,2R)-[3-chloro-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid, 1,1-dimethylethyl ester 2a was prepared for the total synthesis of the HIV protease inhibitor Atazanavir. The diastereoselective reduction of (1S)-[3-chloro-2-oxo-1-(phenylmethyl)propyl] carbamic acid, 1,1-dimethyl-ethyl ester 1 was carried out using microbial cultures among, which Rhodococcus. Brevibacterium. and Hansenula strains reduced 1 to 2a. Three strains of Rhodococcus gave >90% yield. A diastereomeric purity of >98% and enantiomeric excess of >99.3% were obtained for alcohol 2a. (C) 2003 Elsevier Ltd. All rights reserved.