Candida antarctica lipase-catalyzed doubly enantioselective aminolysis reactions. Chemoenzymatic synthesis of 3-hydroxypyrrolidines and 4-(silyloxy)-2-oxopyrrolidines with two stereogenic centers

Aminolyses of racemic and prochiral 3-hydroxyesters with racemic amines are effectively catalyzed by Candida antarctica lipase. In these processes, th e simultaneous resolution of the ester and the amine, or the corresponding asymmetrization-resolution, takes place. In all cases, the high enantiosele ctivity shown by the lipase toward all the reactants allows the preparation of enantiopure 3-hydroxyamides with very high diastereomeric ratios. These 3-hydroxyamides are used as starting materials in the synthesis of 3-hydro xy- and 2-oxopyrrolidines, both containing two stereogenic centers in their structures.