Enantio- and regiospecific partial hydrolysis of racemic diol diacetates by pig liver esterase

The high enantio- and regiospecificity reported from this laboratory for the hydrolysis of the diacetate (±)-2 with pig liver esterase to yield enantiomericly pure monoacetate (+)-3a has been investigated further to define some of the structural features responsible for this unusual degree of specificity. The hydrolysis of the isomeric (±)-5 was found to proceed with identical specificity both qualitatively and quantitatively, indicating that the enzyme recognizes the overall geometry of these substrates but is unable to distinguish between the CF 2 group and the oxygen bridge.Partial hydrolysis of a monocyclic diacetate showed parallel enantioselectivity but proceeded with only 25% ee.It is concluded that conformationally stable molecules may offer favorable targets for regio and/or enantioselectivity in PLE reactions