Stereoselective Formal [3 + 3] Cycloaddition Approach to <i>cis-</i>1-Azadecalins and Synthesis of (−)-4<i>a</i>,8<i>a</i>-<i>diepi</i>-Pumiliotoxin C. Evidence for the First Highly Stereoselective 6π-Electron Electrocyclic Ring Closures of 1-Azatrienes
作者:Heather M. Sklenicka、Richard P. Hsung、Michael J. McLaughlin、Lin-li Wei、Aleksey I. Gerasyuto、William B. Brennessel
DOI:10.1021/ja020698b
日期:2002.9.1
Evidence is described here to support that a highly stereoselective 6pi-electron electrocyclic ring closure of 1-azatrienes is a key step in formal [3 + 3] cycloaddition or annulation reactions of chiral vinylogous amides with alpha,beta-unsaturated iminium salts. This would represent the first highly stereoselective 6pi-electron electrocyclic ring closure of 1-azatrienes. We have also unambiguously
此处描述的证据支持 1-氮杂三烯的高度立体选择性 6pi 电子电环闭合是手性乙烯基酰胺与 α,β-不饱和亚胺盐正式 [3 + 3] 环加成或环化反应的关键步骤。这将代表 1-氮杂三烯的第一个高度立体选择性的 6pi 电子电环闭合。我们还明确地证明了这些特定的闭环是可逆的,导致主要的非对映异构体在热力学上也更稳定,并且旋转偏好也可能起作用。此处说明了合成应用,以立体选择性地将所得二氢吡啶转化为在 C2 和 C2a 处具有独特反相对立体化学的顺式 1-氮杂萘烷,从而合成 (-)-pumiliotoxin C 的表观异构体。