KINETICS OF CARBENIUM ION ADDITIONS TO METHYLENECYCLOALKANES - CYCLOALKYL CATION STABILITIES ARE NOT PREDOMINANTLY CONTROLLED BY STRAIN

Kinetic investigations of the reactions of the (p-anisyl)phenylcarbeni um tetrachlordborate (1 BCl4- with methylenecycloalkanes (ring size 3- 12 and 15) have-been performed. The second-order rate constants correl ate with the solvolysis rates of the corresponding cycloalkyl derivati ves, though none of the ring carbons is rehybridized in the rate-deter mining step (electrophilic attack of 1 at the CC double bond). A simpl e explanation fdr the observed rate effects cannot be given, and it is claimed that the common rationalization of cycloalkyl solvolysis rate s by differences of internal strain has to be modified.