Intramolecular homolytic addition to the CN group was observed for the first time. As the result of the reaction, and the subsequent hydrolysis of the cyclization product, cyanoalkyl radicals of type RĊHXCN, where X is a chain of three carbon atoms and R is hydrogen or alkyl, are converted in aqueous solution into cycloalkanones . The cyanoalkyl radicals, in which X is a chain 4 or 5 C atoms, are partially converted to the corresponding cycloalkanones.