CHLOROPEROXIDASE-CATALYZED ASYMMETRIC-SYNTHESIS - ENANTIOSELECTIVE REACTIONS OF CHIRAL HYDROPEROXIDES WITH SULFIDES AND BROMOHYDRATION OF GLYCALS

This paper describes the use of chloroperoxidase (CPO) from Caldanomyces fumago in the oxidation of sulfides to prepare (R)-sulfoxides with excellent ee (97-100%) and yield (66-92%) using H2O2 as oxidant. When racemic 1-phenylethyl hydroperoxides were used in the oxidation of sulfides, the corresponding (R)-alcohol generated from the oxidant and the unreacted (S)-hydroperoxide were recovered with high enantiomeric purity. The enantioselectivity in the enzymatic asymmetric oxidation was found to depend on the concentrations of the substrate and enzyme. Chloroperoxidase was also used in the regioselective bromohydration of certain saccharide glycals with KBr and H2O2 to give the corresponding 2-deoxy-2-bromo saccharides.