Abstract: Improvement in the known process for producing organic cyclic hydroperoxides, which process includes oxidizing a compound of the formula ##STR1## wherein Ar is an aromatic or saturated cycloaliphatic radical and each R is an aliphatic hydrocarbon radical or a hydrogenated bicyclic terpene hydrocarbon hydroperoxide with an oxygen-containing gas at a temperature of about 80.degree.-150.degree. C under a pressure of about atmospheric up to about 10 atms., wherein the product, when produced by this process, has an improved activity on the catalysis of olefin polymerization if the oxidation reaction is halted at the point where the produced hydroperoxide has a concentration in the reaction mass of about one to less than 5%.