Stereochemical Control of Microbial Reduction. 17. A Method for Controlling the Enantioselectivity of Reductions with Bakers' Yeast

Article abstract of DOI:10.1021/jo00015a038

The stereoselectivity of the bakers' yeast catalyzed reduction of β-keto esters to optically active β-hydroxy esters can be controlled by the introduction of a third reagent.To gain insight into the mechanism of this enzymatic reduction, β-hydroxy ester oxidoreductases were isolated from the cells of raw bakers' yeast.Four dominant competing enzymes were isolated, purified, and characterized.Among these, two reduce β-keto esters stereospecifically to the corresponding D-β-hydroxy esters.The other two afford the L-hydroxy esters.The rates of enzymatic reduction were determined in the presence and absence of the additives.