ASYMMETRIC REDUCTION OF ALPHA,BETA-UNSATURATED CYCLIC-KETONES BY A YEAST

The asymmetric reduction of the carbon-carbon double bond of alpha,bet a-unsaturated cyclic compounds proceeds with high enantioselectivity w hen catalyzed by Yumadazyma farinosa IFO 10896. Microbial reduction of 2-methyl-2-cyclohexen-1-one followed by PCC oxidation affords the opt ically active (R)-2-methyl-1-cyclohexanone of 95% ee. On the other han d, the sequential reactions of O-2-propylidenel-cyclohexanone gives th e unsaturated ketone possessing an S-configuration at the C-2 position .