In recent years, bakers' yeast (Saccharomyces cerevisiae) has been widely employed for the stereoselective reduction of &keto esters, la a-keto esters, lb &keto phenyl sulfides, lc or a, P- unsaturated carbonyl compounds. ld Among many applications of bakers' yeast in organic synthesis, the reduction of carbonyl groups to their hydroxy groups is one of the most extensively studied. However, the mechanistic details of bakers' yeast reduction of ...