Photochemical transformations. 32. Stereochemical course and stereochemical requirement for activation of photosolvolysis and photorearrangements in a chlorobenzobicyclo[2.2.2]octadienyl system
作者:Stanley J. Cristol、Wayne A. Dickenson、Marilyn K. Stanko
DOI:10.1021/ja00343a023
日期:1983.3
The epimers 6-anti- and 6-syn-7-dichloro-2,3-benzobicyclo(2.2.2)octa-2,5-diene (7-Cl and 8-Cl) have been subjected to irradiation in wet acetonitrile at 254 nm. The epimer 7-Cl with chlorine anti to the benzene ring chromophore is photoactive, giving photo-Wagner-Meerwein isomerization and photosolvolysis to Wagner-Meerwein rearranged acetamides. Both the isomerization and the solvolysis (photo-Ritter
差向异构体 6-anti- 和 6-syn-7-dichloro-2,3-benzobicyclo(2.2.2)octa-2,5-diene(7-Cl 和 8-Cl)已在湿乙腈中进行辐照254 纳米。具有抗苯环生色团氯的差向异构体 7-Cl 是光敏的,使 Wagner-Meerwein 异构化和光溶剂分解为 Wagner-Meerwein 重排乙酰胺。异构化和溶剂分解(光-里特反应)都是非立体特异性的,尽管顺式氯乙烯基的迁移发生在适度优先于反苯并基团的迁移中。合成氯化物 8-Cl 相对光惰性,不会产生可归因于光溶剂分解或光-Wagner-Meerwein 异构化的产物。