An optically active vinylic sulfoxide bearing a leaving group at the γ-position was stereoselectively transformed into a chiral cyclopropane by means of a Michael addition with an allylmagnesium bromide. The Michael induced ring-closure reaction requires both allylmagnesium bromide as a uncleophile and chloride as a leaving group for high diastereoselectivity. The absolute stereochemistry of the cycloadduct was confirmed by X-ray analysis.
                                    通过与
烯丙基溴化镁的迈克尔加成反应,一种在 γ 位带有离去基团的光学活性
乙烯基亚砜被立体选择性地转化为手性
环丙烷。迈克尔诱导的闭环反应需要
溴化烯丙基
镁作为不亲和基和
氯化物作为离去基团才能实现高非对映选择性。通过 X 射线分析确认了环加合物的绝对立体
化学性质。