Chiral bipyrindine and biquinoline ligands: Their asymmetric synthesis and application to the synthesis of trans-whisky lactone

Chiral bipyrindine and biquinoline which have been reported to be efficient Ligands for the construction of chiral copper catalysts, were synthesized enantioselectively by rising Mn-salen catalyzed asymmetric epoxidation as a key step. Enantioselective synthesis of trans-whisky lactone was then achieved by way of enantiospecific ring expansion reaction of oxetane with a chiral copper catalyst bearing the bipyrindine Ligand as a chiral source.