Chemoenzymatic resolution of racemic Wieland-Miescher and Hajos-Parrish ketones.

Enantiospecific microbial reduction of bicyclic ketones was described. Racemic Wieland-Miescher ( 1) and Hajos-Parrish ( 2) ketones were used as substrates. In a 4-h biotransformation of Hajos-Parrish ketone ( 2) using the strain of Didymosphaeria igniaria an optically pure ketone ( R)- 2 was obtained, whereas the ( S)- 2 ketone underwent reduction to (4a S,5 S)- 4 alcohol with 100% of enantiomeric excess and with over 60% of diastereoisomeric excess. Jones oxidation of the alcohol obtained in the biotransformation gave an optically pure ketone ( S)- 2. Enzymatic system of Coryneum betulinum reduced the ( R)- 2 ketone to (4a R,5 S)- 4 alcohol with a high enantiomerical purity in a 6-day reaction. Wieland-Miescher ( 1) ketone was transformed by these microorganisms in an analogous way, but the reaction times were longer. [ABSTRACT FROM AUTHOR]