A Study of Cations Derived from exo-2-Aryl-1,3,3- and exo-2-Aryl-1,5,5-trimethylbicyclo[2,2,1] heptan-endo-2-ols

Abstract

The reactions of exo-2-aryl-1,3,3- and exo-2-aryl-1,5,5-trimethylbicyclo[2,2,1]heptan-endo-2-ols in strong acid are reported. The equilibration of 2-(4'-methoxyphenyl)-3,3,endo-6-trimethylbicyclo- [2,2,1]hept-2-yl cation and the exo-6-methyl isomer both formed from 2-(4'-methoxyphenyl)-1,3,3- trimethylbicyclo[2,2,1]hept-2-yl cation is considered to occur by an elimination-addition mechanism. At higher temperatures the bicyclic skeleton collapses to give monocyclic allylic cations. The ¹³C N.M.R. spectra of these ions are reported.