作者:Jiru Shao、Yue Fu、Sunewang R. Wang
DOI:10.1021/acs.orglett.3c00025
日期:2023.1.27
Recyclization of the ring-opening species of alkyl cyclopropyl ketones to cyclopentanones, which proceeds through an unfavored 5-endo-trig cyclization predicted by Baldwin’s rules, is elusive. Herein, as assisted by a strong aryl donor and the Thorpe–Ingold strain on a quaternary cyclopropyl center, stereoconvergent direct ring expansion of cyclopropyl ketones to cyclopentanones promoted by TfOH or BF3·Et2O is
烷基环丙基酮的开环物质再循环为环戊酮(通过 Baldwin 规则预测的不利 5-内-trig 环化进行)是难以捉摸的。在此,在强芳基供体和季环丙基中心上的 Thorpe-Ingold 应变的协助下,描述了由 TfOH 或 BF 3 ·Et 2 O促进的环丙基酮立体收敛直接扩环成环戊酮,提供了多取代环戊酮的模块化结构从醛、烷基甲基酮和 α-酮酯中分三步分解。