Asymmetric Addition of Diethyl Zinc to Benzaldehyde Catalyzed by Chiral Diamine Ligand and Ti-diamine Modified Complex Derived from D-mannitol

Modified procedure for preparation of chiral: 3,4-Diazido-1, 2:5, 6-di-O-isopropylidene-Dmannitol from the corresponding bismesylate and new chiral ligand: 3, 4-diamino-1, 2:5, 6-Oisopropylidene-D-mannitol was described. The application of both diamine and Ti-diamine complex as catalysts in enantioselective addition of diethyl zinc to prochiral benzaldehyde was described. High enantioselectivity up to 93% e.e. was achieved. The standard analytical measurements including optical activity of the diazide, diamine and the determination of optical purity of the resulting alcohol were reported.