Solvolysis of 2-aryl-exo-5,6-trimethylene-2-norbornyl p-nitrobenzoates as a reference of 2-aryl-2-norbornyl p-nitrobenzoates solvolysis
作者:Ken'ichi Takeuchi、Takeshi Kurosaki、Kunio Okamoto
DOI:10.1016/s0040-4020(01)83122-7
日期:1980.1
l system, with its low exo/endo rate ratio, 11.2, is known to solvolyse without significant σ-participation, the tertiary derivatives should also undergo solvolysis without σ-participation. Consequently, the similarities in the solvolytic behaviors between the two systems (5 vs 7; 6 vs 8) strongly support the previous conclusion that σ-participation is unimportant in the solvolysis of 5.
的2溶剂分解的速率-芳基-外- 5,6 -三亚甲基-外-和内- 2 -降冰片基p -nitrobenzoates(7和8,分别地)与代表取代基[ p -CH 3 O,p -CH 3,在80%的丙酮水溶液中测定H,m -CF 3,p -CF 3和3,5-(CF 3)2 ],并将其与母体2-芳基-exo-和内基-2-降冰片基p进行比较-硝基苯甲酸酯(5和6)。内-对-硝基苯甲酸酯()的速率比基本上是恒定的,并且对于这些取代基而言接近1,这表明三亚甲基桥向C 2-位的扰动实际上是可忽略的。外-对-硝基苯甲酸酯的比率()在研究的反应范围内也可以视为不变的。所述外型/内型速率比()是246(p -CH 3 O),196(P -CH 3),129(H),80(米-CF 3),90(p -CF3)和89 [3,5-(CF 3)2 ],与相应的比率相同。这些对硝基苯甲酸酯(7和8)的溶剂化物主要提供(> 97%)外醇。由于已知低exo