Comparison of the ozonolysis products of the methylnaphthalenes and dimethylnaphthalenes in hexane, methanol, and water

The ozonolyses of 1- and 2-methylnaphthalene and 1,2-, 1,3-, 1,4-, and 2,3-dimethylnaphthalene were performed in dilute aqueous solution, and the products which resulted were compared to products from similar reactions performed in n-hexane and methanol. Gas chromatography and gas chromatography-mass spectrometry were used as the primary instrumental methods of analysis because of the low concentrations of products formed in the aqueous reactions. Gas chromatography-Fourier transform infrared spectrometry was used to supplement the mass spectrometric data on the products formed in the organic solvents. All products characterized in the three solvents resulted from the normal ozonolysis of either one or two double bonds in the naphthalene ring system. The products resulting from the ozonolysis of two double bonds were typical of what had been reported previously in the literature. The products which resulted from the ozonolysis of only one double bond were not expected based on previous ozonolysis studies. These compounds were previously unreported in the literature. The reactions in water yielded large amounts of these mono-ozonolysis products compared with the reactions in n-hexane and methanol. A second major difference in the aqueous ozonolyses was that these reactions yielded aldehydes and ketones exclusively as products. The reactions in the organic solvents contrasted sharply with the;reactions in water by yielding large amounts of carboxylic acids as well as aldehydes and ketones; (\u271)DOE Report IS-T-1106. This work was performed under Contract No. W-7405-eng-82 with the U.S. Department of Energy