Highly enantioselective preparation of C-2-symmetrical diols: microbial hydrolysis of cyclic carbonates

A new type of microbial enantioselective hydrolysis of C-2-symmetrical cycl ic carbonates is disclosed. During the screening test of the five-membered substrate (4,5-dimethyl-1,3-dioxolan-2-one 5), Pseudomonas diminuta was sel ected as the best strain to perform the stereoselective hydrolysis. The rea ction of dl-5 with this microorganism in aqueous media containing THF as th e co-solvent afforded (S,S)-5 and (R,R)-butanediol 1 in excellent yields. I t was found that the ring size did not affect the reactivity and enantiosel ectivity although the enzyme had a high substrate specificity for the side chain. A six-membered cyclic carbonate, dl-4,6-dimethyl-1,3-dioxan-2-one 6, was smoothly hydrolyzed with higher enantioselectivity to afford the optic ally active (S,S)-6 and (R,R)-2,4-pentanediol 2. (C) 2000 Elsevier Science Ltd. All rights reserved.