Chiral Preparation of C2-Symmetric 4-Cyclopentene-1,3-diol

Abstract

Optically pure C2 -symmetric 4-cyclopentene-1,3-diol has been prepared in both enantiomeric forms from racemic (3aS*,4R*,7S*,7aS*)-3a,4,7,7a-tetrahydro-4,7-methano-1H-inden-1-one by employing lipase-mediated kinetic resolution as the key step. As a result, the known (3aS*,4R*,7S*,7aS*)-3a,4,7,7a-tetrahydro-4,7-methano-1H-inden-1-one is transformed into (1′S*,3′S*,3′aR*,4′S*,7′R*,7′aS*)- 2′,3′,3′a,4′,7′,7′a-hexahydro-3′-hydroxy-4′,7′-methano-1′H-inden-1′-yl benzoate, via stereo- and regioselective hydride reduction of epoxy ketone and sequential benzoylation, which is resolved under transesterification conditions in the presence of lipase. The hydride reduction of benzoate and acetate gives the corresponding chiral diols, which are further transformed into both enantiomers of C2 -symmetric 4-cyclopentene-1,3-diol via a retro-Diels-Alder reaction.