pH-controlled regioselective nucleophilic ring-opening of epoxide: an improved process for the preparation of ()-(-)- or ()-(+)-3-hydroxytetrahydrofuran.

An environmentally benign, cost-effective and scalable process for the preparation of both the enantiomers of 3-hydroxytetrahydrofuran has been developed. pH-Controlled ring opening of enantiomerically pure epichlorohydrins with cyanohydrin is the key step of the process. The entire protocol does not require any column purification.