Microbial Baeyer–Villiger Oxidation of Prochiral Polysubstituted Cyclohexanones by Recombinant Whole‐Cells Expressing Two Bacterial Monooxygenases

The microbial Baeyer–Villiger oxidation of prochiral 3,5‐dimethylcyclohexanones bearing various functionalities with recombinant E. coli cells overexpressing cyclohexanone monooxygenase from Acinetobacter sp. NCIMB 9871 and cyclopentanone monooxygenase from Comamonas sp. NCIMB 9872 has been investigated. A distinct difference in substrate specificity and stereoselectivity of the two enzymes was observed, and enantiocomplementary products were obtained in some cases. The biocatalytic systems enabled access to chiral lactones as valuable intermediates for the total synthesis of various natural compounds. Substituents with varying lipophilicity and hybridization have been prepared by a diastereoselective synthetic route and subsequently bio‐transformed for the investigation of conformational and electronic effects on the biooxidation,. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)