A highly enantioselective synthesis of optically active α-substituted ketones can be achieved by using a reaction sequence involving a stereoselective anti-SN2′-allylic substitution in the presence of CuCN·2LiCl, followed by the oxidation of the intermediate cycloalkenyllithium species using B(MeO)3/NaBO3·4H2O. The substitution reaction proceeds with a perfect transfer of chirality.
allylic substitution - organozinc - organocopper - chiral α-substituted ketones