Microbial Oxidation of 1,2-Diols Bearing a Substituent with an Oxyfunctional Group: Preparation of Optically Active 1,2-Diols and α-Hydroxy Ketones

The preparation of optically active 1,2-diols bearing a substituent with a benzyloxy group at the terminus has been achieved by microbial enantioselective oxidation of the racemic compounds. In the screening test, Ochrobactrum sp. MU2293 was selected as the best strain to perform the enantioselective oxidation of (+/-)-4-benzyloxybutane-1,2-diol to give the corresponding 4-benzyloxy-1-hydroxybutan-2-one and the remaining (R)-diol with a high ee. This microbial oxidation was applicable to other substrates bearing a substituent with a different carbon number. On the other hand, Bacillus sp. MU2289 catalyzed the oxidation of the 1,2-diols to afford the corresponding alpha-hydroxy ketones and the (S)-diols as the remaining substrates with the opposite absolute configuration.