‘Designer yeast’: a new reagent for enantioselective Baeyer–Villiger oxidations

Abstract

The catalytic repertoire of baker's yeast has been expanded to include enantioselective Baeyer–Villiger oxidations. To create this catalyst, the Acinetobacter sp. cyclohexanone monooxygenase gene was inserted into a yeast expression vector and this was used to create a ‘designer yeast’ that performed oxidation reactions. Whole cell-mediated Baeyer–Villiger reactions were carried out on a 1.0 mmol scale and several cyclic ketones were converted in 20–30 h into the corresponding lactones in isolated yields of 60–83%. Under the reaction conditions, ketone reduction constituted only a minor side-reaction. Oxidation of prochiral 4-substituted cyclohexanones produced lactones with very high enantioselectivities.