Stereoselective enone reductions by Saccharomyces carlsbergensis old yellow enzyme

A series of 2- and 3-alkyl-substituted 2-cyclohexenones were shown to be substrates for the old yellow enzyme of Saccharomyces carlsbergensis expressed in Escherichia coli cells. Chemo- and stereoselective alkene reductions were observed, and the absolute configurations of the products could be predicted from the X-ray crystal structure of the protein. No competing carbonyl reductions were detected. These results support the notion that enzymes of this family may be useful in stereoselective organic synthesis. (c) 2006 Elsevier B.V. All rights reserved.