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 ...