Bakers′ Yeast Reduction of α-Diketones: Investigation and Control of the Enzymatic Pathway

Optically pure α-hydroxyketones and α-diols are obtained through a regio- and stereocontrol of the reduction of acyclic α-diketones by bakers′ yeast. An investigation of the enzymatic system clearly demonstrates the role of two enzymes operating in sequence. An alcohol dehydrogenase is implicated in the initial reduction of the α-diketone, and the resulting α-hydroxyketone is subsequently reduced by a glycerol dehydrogenase. The first reductive step is found to direct the stereochemical outcome of the entire reaction.