Unusual Cyclopropanation of 9-Bromocamphor Derivatives: A Novel Formal C(1)−C(7) Bond Cleavage of Camphor
作者:Wei-Dong Z. Li、Yu-Rong Yang
DOI:10.1021/ol051141e
日期:2005.7.1
to be the sole effective reaction medium. Tricyclic compound 3 undergoes a facile tandem Wagner-Meerwein rearrangement-cyclopropyl ring-opening under mild acidic conditions, leading to norbornenyl derivative 12 and subsequent Meinwald rearrangement of bicyclic epoxide 13 to a formal C(1)-C(7) bond cleavage product 14.
[反应:见正文]在温暖的DMSO中,叔丁醇钾(或氢化钠)的作用使9-溴樟脑衍生物1异常环化为7-螺环-环丙基樟脑衍生物3。已证明C(2)处的外羟基和非氢内取代基是必不可少的结构元素,并且溶剂DMSO已被证明是唯一有效的反应介质。三环化合物3在温和的酸性条件下容易进行串联的Wagner-Meerwein重排-环丙基开环,导致降冰片烯基衍生物12和随后的Meinwald重排双环环氧化物13形成正式的C(1)-C(7)键裂解产物14 。