diastereomeric mixture. Each diastereomer obtained had high optical purity. The reaction of the α-seleno carbanion derived from the bis(phenylseleno)acetal also showed high enantioselectivity. The stereospecific elimination of the isolated diastereomers on treatment with methanesulfonyl chloride and triethylamine afforded axially chiral benzylidenecyclohexanes with high enantioselectivities up to 99% ee.
在双(
恶唑啉)存在下,衍生自1-苯基-1-(苯
硫基)-1-(三
丁基锡烷基)
甲烷的α-
硫代碳负离子与4-取代的
环己酮的对映选择性反应得到产物,为非对映异构体混合物。所获得的每种非对映异构体均具有高光学纯度。衍生自双(苯基
硒代)
缩醛的α-
硒代碳负离子的反应也显示出高对映选择性。用甲
磺酰氯和
三乙胺处理分离的非对映异构体的立体定向消除,提供了轴向手性亚苄基
环己烷,具有高达99%ee的高对映选择性。