EFFICIENT SYNTHESES OF ENANTIOMERICALLY PURE 1,2-DICYCLOHEXENYL-1,2-ETHANEDIOL AND 1,2-DICYCLOHEXYL-1,2-ETHANEDIOL USING B-2-CYCLOHEXEN-1-YL-DIISOPINOCAMPHEYLBORANE

The reaction of (+)-B-2-cyclohexen-1-yldiisopinocampheylborane with gl yoxal at -78 degrees C yields 98% stereoisomerically pure (1S,2S,1'R,1 '' R)-(+)-1,2-bis(2-cyclohexenyl)-1,2-ethanediol in 81% yield. A simp le crystallization of the above diol from hexane followed by hydrogena tion over Raney Ni provides an essentially quantitative yield of enant iomerically pure (S,S)-1,2-dicyclohexyl-1,2-ethanediol. (C) 1997 Elsev ier Science Ltd. All rights reserved.