Lipase-catalyzed asymmetric desymmetrization of prochiral 2,2-disubstituted 1,3-propanediols using 1-ethoxyvinyl benzoate

The lipase-catalyzed asymmetric desymmetrization of the prochiral 2,2-disubstituted 1,3-propanediols was studied using various types of 1-ethoxyvinyl esters (1a-i). Although 1a-e with aliphatic acyl groups were not sufficient, use of the benzoate (1f) in combination with Candida rugosa lipases converted acyclic diols (2, 6) and cyclic diols (11-14) to the optically active compounds (3f, 7f, 15f-18f), bearing a quaternary carbon center, with moderate-to-high optical yields. These products were fairly stable against racemization under acidic conditions.