Lipase-catalyzed alcoholysis of diol dibenzoates : Selective enzymatic access to the 2-benzoyl ester of 1,2-propanediol and preparation of the enantiomerically pure (R)-1-O-benzoyl-2-methylpropane-1,3-diol

Enzymatic debenzoylation of 1,2-propanediol dibenzoate with 1-octanol has been studied in organic solvent using lipases from different sources. In general a slow, highly regioselective alcoholysis in diisopropyl ether affords exclusively a monoester benzoylated at the secondary hydroxy group although the reaction proceeds with low enantioselectivity. In the presence of Pseudomonas cepacia lipase absorbed onto celite, a faster reaction allows the preparation of the 2-benzoyl ester of (R)-1,2-propanediol (82% ee) and the enantiomerically pure (R)-1-O-benzoyl-2-methylpropane-1,3-diol (>98% ee).