Biocatalytic reductive desymmetrization of prochiral 1,3-diketone and its application to microbial hormone synthesis

Abstract

Microorganisms screened from yeast and bacteria were used as biocatalysts to synthesize optically active hydroxyketones with an asymmetric quaternary carbon containing adjacent ethyl and methyl groups based on the microbial reductive desymmetrization of prochiral cyclic 1,3-diketones. Candida cacaoi NBRC 10231 and Pichia farinosa NBRC 10896, two types of yeast species, were found to preferentially reduce only one carbonyl group to give the (2R,3S)-form. In contrast, three types of bacterial species, Morganella morganii NBRC 3168, Providencia rettgeri NBRC 13501, and Escherichia fergusonii NBRC 102419, preferentially produced the (2S,3S)-form with excellent stereoselectivity. Starting from (2R,3S)-hydroxyketone prepared using Candida cacaoi NBRC 10231, which exhibits both high reactivity and stereoselectivity, the characteristic chain structure of avenolide, a type of microbial hormone, was successfully synthesized.