作者:Ashay Patel、Gregg A. Barcan、Ohyun Kwon、K. N. Houk
DOI:10.1021/ja400882y
日期:2013.3.27
A novel stereoselective electrocyclization developed for the total synthesis of reserpine has been explored by both experiment and theory. A stereocenter six atoms away from the newly forming chiral center is responsible for the diastereoselectivity of the ring closure. This stereogenic center, lying at the junction of two six-membered rings, defines the conformation of the substrates' fused ring skeleton
通过实验和理论探索了一种用于利血平全合成的新型立体选择性电环化反应。距离新形成的手性中心六个原子的立体中心负责闭环的非对映选择性。这个立体中心位于两个六元环的交界处,定义了底物稠环骨架的构象,最终区分了过渡态下两种允许的、旋转的三烯几何结构。在不利的过渡态中烯丙基应变的存在导致转矩选择性闭环(dr 高达 15.7:1)。