The titled compunds 1-exo-Cyano-1a,7b-dihydro-1H-cyclopropa[a]naphthalenes(8a), 1-endo-Cyano-1a,7b-dihydro-1H-cyclopropa[a]naphthalenes(8b), were photolyzed in several solvents. The results were: (1) The isomerization proceeded faster in aprotic nonpolar solvents than in polar ones. (2) The 1-endo derivative (8b) rearranged faster than the 1-exo-isomer (8a). (3) 8b was isomerized through Berson-Willcott rearrangement by the fission of bonds C1–C7b and C1–C1a, while 8a gave 1-cyanomethylnaphthalene (5b) as a main product. (4) Examination with an optically active 1-exo derivative (8a) showed that the exo-endo interconversion occured by the simultaneous two centered (30%) and one centered (70%) epimerization.
在几种溶剂中对标题化合物 1-exo-Cyano-1a,7b-dihydro-1H-cyclopropa[a]naphthalenes(8a) 和 1-endo-Cyano-1a,7b-dihydro-1H-cyclopropa[a]naphthalenes(8b) 进行光解。结果如下(1) 异构化在非极性钝化溶剂中比在极性溶剂中进行得更快。(2)1-内向衍
生物(8b)的重排速度快于 1-外向异构体(8a)。(3) 8b 通过 C1-C7b 和 C1-C1a 键的断裂进行 Berson-Willcott 重排而异构化,而 8a 的主要产物是 1-
氰甲基萘(5b)。(4) 用光学活性 1-外向衍
生物(8a)进行的研究表明,外向内向的相互转化是通过同时发生两个中心(30%)和一个中心(70%)的外向二聚发生的。