Solvolysis of 1-[trans-2-(m- or p-substituted phenyl)cyclopropyl]-1-methylethyl p-nitrobenzoates

The solvolyses of 1-[trans-2-(m-or p-substituted phenyl)cyclopropyl] -1-methylethyl p-nitrobznzoates in 80% aqueous acetone have been studied with regard to both reactivity and product composition. For the less reactive substituents such as m-Br, m-Cl, and,m-CF3, the solvolysis products were the corresponding 2-(2-arylcyclopropyl)-2-propanol, indicating the cyclopropylmethyl cation intermediate. The ring-opened products increased as the electron-donating ability of the substituents increased. The application of the Yukawa-Tsuno equation to the reactivity afforded a rho value of -1.43 and r value of 0.59 with a correlation coefficient of 0.997. A large value of r indicates the presence of the allylic cation intermediate where much more charge develops at the benzylic carbon for the derivatives with electron-donating substituents than is the case for the cyclopropylmethyl cation intermediate. Thus the solvolysis reaction proceeds via two independent pathways: one has a cyclopropyl cation intermediate and the other has a homoallylic cation intermediate.