Free-radical reactions of halogenated bridged polycyclic compounds. Part V. The addition of thiols and bromotrichloromethane to 1,2,3,4-tetrachloro-7,7-dimethoxynorborna-2,5-diene and the preparation of 1,2,3,4-tetrachloro-7,7-dimethoxyquadricyclene
作者:D. I. Davies、P. J. Rowley
DOI:10.1039/j39670002245
日期:——
7-dimethoxynorborna-2,5-diene (Ia) affords 1,4,5,6-tetrachloro-7,7-dimethoxynorborn-5-en-2-endo-yl alkyl sulphides (IV) and 1,2,3,5-endo-tetrachloro-6,6-di-methoxynorborn-2-en-7-syn-yl alkyl sulphides (V). Bromotrichloromethane affords 5-exo-bromo-1,2,3,5-endo-tetrachloro-6,6-dimethoxy-7-syn-trichloromethylnorborn-2-ene (XI) as sole product. The results are compared with those of similar reactions of
将硫醇自由基加成到1,2,3,4-四氯-7,7-二甲氧基降冰片-2,5-二烯(Ia)中得到1,4,5,6-四氯-7,7-二甲氧基降冰片-5 -en-2-内-烷基硫化物(IV)和1,2,3,5-内-四氯-6,6-二甲氧基降冰片-2-en-7-顺基烷基硫化物(V)。溴三氯甲烷可提供5- exo-溴-1,2,3,5-内-四氯-6,6-二甲氧基-7-辛基-三氯甲基降冰片-2-烯(XI)为唯一产物。将结果与六氯降冰片二烯(Ib)的类似反应进行了比较,得出的结论是,C-7取代基的大空间尺寸控制自由基的进攻方向。C-7处的甲氧基取代基似乎能以少于氯取代基的硫醇来阻止链转移:相反的情况适用于溴代三氯甲烷的链转移。报道了1,2,3,4-四氯-7,7-二甲氧基四氢环戊烯(XII)的制备。