Asymmetric Bioreduction of a Bulky Ketone: 1-Phenyl-1-(2-phenylthiazol-5-yl)-methanone

We have investigated the preparation of (R)- and (S)-1-phenyl-1-(2-phenylthiazol-5-yl)-methanol by asymmetric bioreduction of the corresponding bulky ketone 1-phenyl-1-(2-phenylthiazol-5-yl)-methanone with whole microbial cells. A short screening of 38 microbial strains allowed the selection of two suitable yeast strains fulfilling enantiocomplementarity. Gram-scale preparations of the S- and R-alcohols were achieved with high yield and high optical purity using, respectively, Saccharomyces montanus CBS 6772 (yield 79%, ee 96%) and Rhodotorula glutinis var. dairenensis MUCL 30607 (yield 96%, ee 91%). The two enantiomeric alcohols prepared are novel compounds described here for the first time.