Facile Synthesis of the Fused 6-6-5 Ring System Containing Chroman Ring from 2-(1-Hydroxy-5-alkenyl)phenol Derivatives via Intramolecular Inverse-Electron-Demand Diels–Alder Reaction
作者:Kedar Shanker Shrestha、Kiyoshi Honda、Masatoshi Asami、Seiichi Inoue
DOI:10.1246/bcsj.72.73
日期:1999.1
A simple and facile synthesis of the fused 6-6-5 ring system, i.e., 1,2,3,3a,4,9b-hexahydrocyclopenta[c][1]benzopyrans, was achieved through the intramolecular [4+2] cycloaddition of o-quinonemethides generated from 2-(1-hydroxy-5-alkenyl)phenol derivatives under acidic conditions. In general, cis-fused tricyclic compounds of 6-6-5 ring system were obtained as the major products. Reactivity and selectivity
通过分子内 [4+2] 环加成实现了稠合 6-6-5 环系统,即 1,2,3,3a,4,9b-六氢环戊二烯 [c][1] 苯并吡喃的简单易行合成在酸性条件下由 2-(1-羟基-5-烯基)苯酚衍生物生成的邻醌甲基化物。一般情况下,主要产物为6-6-5环系的顺式稠合三环化合物。环加成反应的反应性和选择性取决于芳环上和亲二烯烯烃部分中的取代基。