A procedure was suggested for the synthesis of 2,5-dimethyl-2-tert-alkylperoxy-5-lithiooxy-5methyl(phenyl)-5-naphthyl(aryl)alk-3-ynes by the reactions of the corresponding monosubstituted peroxyalkynes with butyllithium, followed by the reactions of the resulting lithium peroxy acetylenides with 4-methoxybenzophenone and 1- and 2-acetonaphthones. Lithium peroxy alcoholates are hydrolyzed with water to form peroxy-containing alcohols and react with methyl iodide in the presence of dimethyl sulfoxide to form the corresponding 2,5-dimethyl-2-tert-alkylperoxy-5-methoxy-5-methyl(phenyl)-5-naphthyl(aryl)alk-3-ynes. The thermal stability of the peroxides prepared was evaluated by thermal analysis.