The electrochemical reduction of tert-butyl p-cyanoperbenzoate in DMF leads to the cleavage of the oxygen-oxygen bond. A subsequent reaction yielding tert-butyl p- cyanobenzoate could be avoided by the addition of a mild acid, with the result that the main reduction peak was affected only by the kinetics of the electron transfer bond fragmentation process. Unusual features of the heterogeneous electron transfer mechanism were ...