Solvolyses of 4-methylene-2ax- and -2eq-adamantylp-toluenesulphonates: Intermediacy of classical carbocation in the axial and ?-bridged carbocation in the equatorialptoluenesulphonate solvolyses
作者:Ken'ichi Takeuchi、Yumiko Kurihara、Takao Okazaki、Toshikazu Kitagawa、Tomomi Kinoshita
DOI:10.1002/poc.610070811
日期:1994.8
The rates and products of solvolyses of 4-methylene-2ax- and -2eq-adamantyl p-toluenesulphonates (tosylates) (4a-OTs and 4e-OTs, respectively) were studied. Compound 4a-OTs solvolysed more slowly than 2-adamantyl tosylate (1) in methanol and 2,2,2-trifluoroethanol (TFE) by factors of 2·3 and 2·5, respectively, at 25°C. However, by taking the inductive decelerating effect of a β-methylene substituent
率和4-亚甲基-2 solvolyses产品斧-和-2当量金刚烷基p -toluenesulphonates(甲苯磺酸酯)(图4a-OTS和4e-OTS,分别地)进行了研究。在25°C下,化合物4a-OTs在甲醇和2,2,2-三氟乙醇(TFE)中的溶解速度比甲苯磺酸2-金刚烷基酯(1)慢2到3倍和2到5倍。但是,考虑到β-亚甲基取代基的感应减速作用,显示出α参与率可提高50倍。4a-OTs在甲醇,80%丙酮和TFE中的溶剂分解产物在100℃下分别为2斧-和2当量-烷氧基(或羟基)-4- methyleneadamantanes(-OR 4a和4E-OR,分别地),外切-4-烷氧基(或羟基)-5-亚甲基原金刚烷(exo-5-OR)和5- [烷氧基(或羟基)甲基] -4-原金刚烷(6-OR),金刚烷基与原金刚烷基的产物比例为39:61(在甲醇中),56:44(在80%丙酮中)和71:29(在T