When cyclic ketones are allowed to react with anhydrous hydrogen peroxide three types of peroxides may form: 1-hydroxycyclanyl hydroperoxide-1 (I), 1, l'-dihydroxydicyclanyl peroxide-1, l'(11) and cyclanylidene peroxides (111, IV, and V). Using cyclopentyl as the cyclopolymethylene radical these may be illustrated as follows 0-o\