作者:Charles W. Jefford、Arlette Delay、Timothy W. Wallace、Ulrich Burger
DOI:10.1002/hlca.19760590708
日期:1976.11.3
The addition of difluorocarbene to bicyclo[2.2.2]octa-2,5-diene gave the exo and endo 1:1 cyclopropane adducts. In contrast to norbornadiene, no homo-1,4 adduct was formed. The adducts were thermally stable under the conditions of their formation and separation (<170°). However, smooth equilibration was achieved on heating at 250° for 36 h. The same mixture resulted from either isomer. At 250° ΔΔG
将二氟卡宾加至双环[2.2.2] octa-2,5-二烯中,可得到外向和内向1:1的环丙烷加合物。与降冰片二烯相反,没有形成均一的-1,4加合物。加合物在其形成和分离(<170°)的条件下是热稳定的。但是,在250°C加热36小时后,达到了平稳的平衡。两种异构体均产生相同的混合物。在250℃ΔΔ ģ = 1.83千卡/摩尔; 该内异构体是更稳定。加热到更高的温度会引起分解,而不是进一步与分子内[2 + 2]环化产物发生反应。在外推至相同温度时,动力学和热力学产物组成基本相同。内/外25°时19-22。讨论了顺式稠合的环丙烷部分的环加成和立体突变发生的机理。