作者:W. E. Billups、Rajesh K. Saini、Vladislav A. Litosh、Lawrence B. Alemany、William K. Wilson、Kenneth B. Wiberg
DOI:10.1021/jo011144e
日期:2002.6.1
Thermolysis of spiro[2.4]hepta-1,4,6-triene (1a) at 50 degrees C yielded bicyclo[3.2.0]hepta-1,3,6-triene (5), which dimerized in two different fashions to form cyclobutanes. The 1,2-dimethyl and 1-propyl derivatives of 1a also rearranged at 50 degrees C, but at a faster rate, each yielding a pair of cyclobutane dimers. The structures of these symmetrical dimers were investigated by 1D and 2D NMR and
螺[2.4]庚-1,4,6-三烯(1a)在50摄氏度下热解,生成双环[3.2.0]庚-1,3,6-三烯(5),其以两种不同方式二聚形成环丁烷。1a的1,2-二甲基和1-丙基衍生物也于50摄氏度重新排列,但速度更快,每个都产生一对环丁烷二聚体。这些对称二聚体的结构通过1D和2D NMR以及NOE差异光谱进行了研究。从头算计算表明,这两种应变烯烃1a和5的可比能量比norborna-1(7),2,5-三烯低约50 kcal / mol,因此被排除为反应中间体。