Db. Berkowitz et Jh. Maeng, ENANTIOSELECTIVE ENTRY INTO BENZOXABICYCLO[2.2.1]HEPTYL SYSTEMS VIA ENZYMATIC DESYMMETRIZATION - TOWARD CHIRAL BUILDING-BLOCKS FOR LIGNAN SYNTHESIS, Tetrahedron : asymmetry, 7(6), 1996, pp. 1577-1580
The meso diacetate, 9, available in seven steps from piperonal, is eff
iciently desymmetrized with preferential cleavage of the R-arm-acetate
under catalysis by porcine pancreatic lipase in 10% DMSO-phosphate bu
ffer, pH 8. The resulting monoacetate 12, a potentially useful chiral
building block for the synthesis of derivatives of the Podophyllum lig
nans, is obtained in good chemical yield (66-83%) and in high optical
yield (95% ee) on a multigram scale. (C) 1996 Elsevier Science Ltd