Regiospecificity and Enantiospecificity in Microbiological Reduction of Acyclic β-Diketones

A screening of microorganisms has been performed to study the regio- and stereospecificities of the reduction of carbonyl groups in 2,4 and 3,5 diketones to obtain all stereoisomers. (2S), (2R), (3S), (3R) and (5R) ketols are obtained along with (2S, 4S) and (3S, 5S) diols often in high optical yields. Chemo-enzymatic methodologies to obtain stereoisomers not reached by direct microbiological reduction are discussed.