Billups W. E., Luo Weimei, Lee Gon-Ann, Chee Jennifer, Arney Benny E., Wiberg K. B., Artis Dean R.
Department of Chemistry, Yale University, New Haven, Connecticut 06520.
J Org Chem. 1996 Jan 26;61(2):764-770. doi: 10.1021/jo951559y.
Bicyclo[4.1.0]hept-1,6-ene has been generated by elimination of 1-chloro-2-(trimethysilyl)bicyclo[4.1.0]heptane in the gas phase over solid fluoride at 25 degrees C. The cyclopropene dimerizes by a rapid ene reaction forming two diastereomeric cyclopropenes. In tetrahydrofuran or chloroform the ene dimers couple to form a single crystalline triene tetramer, whereas a mixture of tricyclohexane tetramers is formed when the neat dimers are allowed to warm to room temperature. Oxidation by dimethyldioxirane or dioxygen gives carbonyl products. Quantum mechanical calculations yielded an increase in strain of approximately 17 kcal/mol over that for 1,2-dimethylcyclopropene. The potential enegy barrier to flexing (folding) along the fused double bond of bicyclo[4.1.0]hept-1,6-ene is only approximately 1 kcal/mol at the highest level of theory investigated.
在25摄氏度下，通过在气相中于固体氟化物上消除1-氯-2-(三甲基硅基)双环[4.1.0]庚烷生成了双环[4.1.0]庚-1,6-烯。环丙烯通过快速的烯反应二聚形成两种非对映异构的环丙烯。在四氢呋喃或氯仿中，烯二聚体偶联形成单晶三烯四聚体，而当纯二聚体升温至室温时会形成三环己烷四聚体的混合物。用二甲基二氧杂环丙烷或氧气氧化会生成羰基产物。量子力学计算表明，与1,2-二甲基环丙烯相比，应变增加了约17千卡/摩尔。在所研究的最高理论水平下，沿双环[4.1.0]庚-1,6-烯的稠合双键弯曲（折叠）的势能垒仅约为1千卡/摩尔。
