Carbon Participation in the Solvolysis of Tertiary Norbornyl Derivatives Norbornanes. Part 15. 6-substituted 2-methylnorbornyl 2-exo- and 2-endo-2,4-dinitrophenyl ethers
作者:Cyril A. Grob、Adrian Waldner
DOI:10.1002/hlca.19830660813
日期:1983.12.14
The solvolysis rates and products of the tertiary 2-methyl-2-exo- and -2-endo-norbornyl 2,4-dinitrophenyl ethers 1 and 2, (X = 2,4-(NO2)22C6H3O) have been determined. The different sensitivities of the rates of these ethers to the inductive effect of substituents at C(6) indicate that graded bridging of C(2) by C(6) occurs in the ionization of the exo-ethers 1, not, however, in the ionization of the
2-甲基-2-外-和-2-内-降冰片基2,4-二硝基苯基醚1和2的溶剂分解速率和产物,(X = 2,4-(NO 2)2 2 C 6 H 3 O)已确定。这些醚的比率的对取代基中的C(6)诱导效应的不同敏感性表明由C(6)分次桥接C(2)的发生在电离外型-醚1,没有,但是,在内-醚2的电离。在两种情况下,水解都会导致2-甲基-2- exo-仅降冰片醇。因此,取代发生在exo系列1的C(2)处,内序列2的C(2)发生反转。结论是,立体电子和极性效应而不是空间体积效应决定了取代度。高的exo /内速率比率的母体降冰片衍生物1a和2a。