作者:Benzion Fuchs、Mordechai Pasternak
DOI:10.1016/s0040-4020(01)88909-2
日期:1981.1
o'-biphenylene) cyclopentadienone-dimers (6a–6c) were prepared and found to undergo photochemically or thermally a 1,3-rearrangement to the centrosymmetrical diketones (11). Only the tetramethyl derivative (6a) undergoes at room temperature a fast, degenerate [3.3] Cope rearrangement with ΔG≠233 = 11.4 kcal mol.−1 All these dimers and rearrangement products appear not to dissociate to their monomers, but react
制备并发现了1,4-二甲基-,1,2,4-三甲基和1,2,4,7-四甲基取代的3,4-(o,o'-联亚苯基)环戊二烯酮二聚物(6a - 6c)经历光化学或热重心对称的二酮的1,3重排(11)。仅四甲基衍生物(6a)在室温下经历快速,简并的[3.3] Cope重排,ΔG ≠ 233 = 11.4 kcal mol。-1所有这些二聚体和重排产物似乎都不会与其单体解离,而是与亲双烯体反应生成加合物(12,13)。调用涉及双自由基中间体(19)的逐步机制。还制备并研究了“混合二聚体”(14)。讨论了决定这些化合物行为的空间和电子效应。