Solvolysis of exo- and endo-5,6-(o-phenylene)- and -(1,8-naphthylene)-2-norbornyl toluene-p-sulphonates

The rates and products of solvolysis of the toluene-p-sulphonates (1)—(8) in acetic acid and formic acid are reported and the nature of the solvolysis intermediates is discussed. A small amount of carbon–carbon bond participation cannot be excluded in the ionisation process in the solvolysis of compound (3), and 95% of the product is formed by migration of the C(1)–C(6) bond. Although a similar rearrangement occurs in the solvolysis of compound (7), no anchimeric assistance is observed in the ionisation, and the rate of solvolysis is determined by steric factors. The possibility of ion-pair return has been investigated in these reactions by comparison of rates of solvolysis with that of 1,2,2-trimethylpropyl p-bromobenzenesulphonate, which confirms the absence of carbon–carbon participation in the ionisation process of all but compound (3). Substantial steric inhibition to ionisation is found in the solvolysis of compounds (4) and (8) and the data are compared with those for other systems.