已经系统地研究了环丁二烯亲二烯(1)与环戊二烯酮的热环加成;立体异构体加合物可通过脱羰作用方便地获得各种四芳基-,甲基三苯基-,三苯基-,三叔丁基-和二甲基二苯基-环辛-1,3,5-三烯衍生物异戊二烯桥键合的价互变异构初级产物的开环,即。双环[4.2.0]辛二烯。这些化合物为研究电价互变异构体之间的平衡,热交联的范围和机理(例如不对称取代的环辛烯和热乙烯基-环丙烷(1,3-烯丙基转移)的异构化)提供了有用的模型。和/或所得芳基化的和烷基芳基二氢半bullvalenes的H原子转移歧化。该结果与环辛三烯-二氢半双戊烯转化和随后的重排的双自由基途径最相符。还报道了有用的13 C和1 H nmr结构相关性以及环戊二烯酮的新实例。
bridge adducts; these, on relatively mild thermolysis, yield dihydrosemibullvalene derivatives by a novel sequence including cheletropic loss of carbon monoxide, electrocyclic ring opening of the immmediate substituted bicyclo[4,2,0] octadienes, and intramolecular [π4a +π2a]cycloaddition of the derived cyclooctatrienes. Other pericyclic reactions of compounds related to those of the title compounds
Thermal rearrangement of alkylaryldihydrosemibullvalene derivatives: hydrogen atom transfer processes
作者:S. Greenfield、K. Mackenzie
DOI:10.1016/s0040-4039(01)80227-6
日期:1984.1
Alkylaryldihydrosemibullvalene derivatives, besides exhibiting vinylcyclopropane type rearrangements typical of tetraarylated analogues, also undergo H· atomtransfer from methyl groups, most easily understood in terms of biradical intermediates resulting from alternative modes of cyclopropane ring scission.