allylsilyl alcohols without allylic substituents, the reaction gives dioxaspirodecanes, which are the products of a tandem Sakurai–Prins cyclization. In contrast, allylsilyl alcohols with an allylic substituent (R2≠H) selectively provide oxepanes, thus corresponding to a direct silyl–Prins cyclization. Both types of product are obtained with excellent stereoselectivity. Theoretical studies have been performed
在三甲基甲
硅烷基
三氟甲磺酸酯(TMSOTf)存在下,烯丙基甲
硅烷基醇1和醛的反应观察到两种不同的机理途径。在没有烯丙基取代基的烯丙基甲
硅烷基醇的情况下,反应生成二恶草螺烷,这是串联的Sakurai–Prins环化产物。相反,具有烯丙基取代基(R 2 ≠H)的烯丙基甲
硅烷基醇选择性地提供氧杂
环丁烷,因此对应于直接的甲
硅烷基-普林斯环化反应。两种产品均具有出色的立体选择性。已经进行了理论研究以对观察到的立体选择性获得一些合理化。