Kinetic resolution of (R, S)-1,2-O-isopropylideneglycerol by esterification with dry mycelia of moulds

The esterification of (R, S)-1,2-O-isopropylideneglycerol catalysed by dry mycelia of different moulds in organic solvent was studied. Dry mycelium of Rhizopus oryzae CBS 112.07 and Aspergillus oryzae MIM gave the (R)-ester with moderate optical purity; the kinetic data of the esterification with butyric acid in n-heptane showed an enantiomeric ratio of 3.4 with Rhizopus oryzae and 8.0 with Aspergillus oryzae. The esterification catalysed by Aspergillus oryzae was performed on larger scale (operative volume 2.31) allowing for the production of 2.3 g(-1) of (R)-IPG butyrate with an e.e. = 56% and a molar conversion of 52%. The enantiomerically enriched ester was hydrolysed with thermally-treated cells of Bacillus coagulans: the (S)-ester was obtained as enantiomerically pure molecule, while the alcohol was recovered with e.e. = 90%.