“Top” or “Bottom” Switches of a Cyclohexanone Monooxygenase Controlling the Enantioselectivity of the Sandwiched Substrate

Single mutation at the switch residues F432 (F432I/L) or L435 (L435A/G) efficiently reversed the inherent enantiopreference of WT CHMOAcineto in the Baeyer–Villiger oxidation of various 4-phenyl-cyclohexanone derivatives and 4-alkyl-cyclohexanones, producing a series of substituted lactones with inversed configuration (up to 99% ee and 99% conversion).