Allylic Cations in Solvolysis. A Case of Non-Participation

The rate constants and secondary deuterium Isotope ef\u27fects are measured in the solvo\u27lysis of various allyHc p-nitrobenzoates. The obtained results are explained by differences in inductive effects o>f vardous groups in the side-chain. These results are in keeping with the stepwise mechanism according to which neighboiring group n- and n-paxticiipation is not revealed in the studied solvCJ!lytic reactions

Solvolysis rate of 3-methyl-2- (3-pentynyl) · 2-cyclohexenyl p-nitrobenzoate. A model system for n-participation of the CC triple bond

The synthesis of 3-methyl-2-:(3-rpentynyl)-2-cycloheocenyl p-nitro1benzoa1te is desc["ibed. This ester so1lvolyzes in 97°/o CF3CH20H at 2'5 °C without n-participa:tion of the CC trLple bond, showing solvoiysis rate retardaition in comparison with the saturated anafog. This result is e~piained by electron-withdrawing inductiove e1ffect 01f 1the CC trirple bond. The lo.g k va~ues of alkanyl- (4), alikenyl- (5, 6), and alkyny:l-substitJu·ted (10) esters show good linear correia1tion With the pK. values of the cOirresrponding car:boxyJ'ic acids