Preparative syntheses of optically pure ortho-substituted benzhydrols by asymmetric reductions of the corresponding benzophenones

Article abstract of DOI:10.1016/S0957-4166(00)82179-5

Lithium aluminium hydride previously treated with 2.5 equivalents of (S)-(+) or (R)-(-)-2-(2-iso-indolinyl)butan-1-ol 3 (readily available reagents) reduced the five ortho-substituted benzophenones 4-6, 8 and 10 into the corresponding optically active benzhydrols with nearly 100% enantiomeric excesses. Other examples of asymmetric reductions of prochiral benzophenones are given.