Biotransformations of gamma-methyl-beta-ketosulfones:stereoselectivity of 3-methyl-1-(phenylsulfonyl)hexan-2-one reductions by various yeasts

The stereoselectivity of the reduction of rac-3-methyl1-(phenylsulfonyl)hexan-2-one (1) to 3-methyl1-(phenylsulfonyl)hexan-2-ol (2) diastereomers by more than 20 yeasts was studied. Reduction of carbonyl group in 1 proceeds with a high Re-face enantioselectivity: Candida guillermondii (98.9% e.e.), C. zeylanoides (>99.9%), and Kloeckera apiculata (99.6%), respectively and the (R)-1 enantiomer usually reacted faster. The enantioselectivity was determined by GC on chiral cyclodextrine phases and absolute configurations of products were assigned by NMR spectroscopy and a chemical correlation. Copyright (C) 1996 Elsevier Science Lt