Concomitant Formation of Isomeric 1-, 2-, and 3-Substituted Heptafulvenes from 2-Substituted Tropones and Active Methylene Compounds
作者:Akira Mori、Bing-Zhu Yin、Akihiro Endo、Hitoshi Takeshita
DOI:10.1246/cl.1992.855
日期:1992.5
methyl cyanoacetate and 4-nitrobenzyl cyanide with 2-isopropyl-, 2-methyl-, and 2-phenyltropones in Ac2O gave isomeric 1-, 2-, and 3-substituted heptafulvene derivatives. The mechanism of reaction was explained in terms of a remote nucleophilic attack of the active methylene compounds to acetoxycycloheptatrienylium salt, followed by [1,5] sigmatropic hydrogen shift and elimination of acetic acid.
氰基乙酸甲酯和 4-硝基苄基氰与 2-异丙基-、2-甲基-和 2-苯基托酮在 Ac2O 中的缩合得到异构的 1-、2- 和 3-取代的七富烯衍生物。根据活性亚甲基化合物对乙酰氧基环庚三烯鎓盐的远程亲核攻击来解释反应机理,然后是 [1,5] σ 氢转移和乙酸的消除。