PHOTOCHEMISTRY OF SUBSTITUTED 4,4-DIMETHOXY-2,5-CYCLOHEXADIENONES

4,4-Dimebhoxy-2,5-cyclohexadienones 9-14 were prepared from the corres ponding hydroquinone monomethyl ethers by oxidation with thallium trin itrate in methanol. Irradiation of solutions of 9-13 in methanol with a broad band of UV light centered at 350 nm in a Rayonet reactor affor ded 2-cyclopentenone derivatives 15-19 in moderate to excellent yields , whereas irradiation of 14 in methanol gave phenol 8 along with other unidentified products. Irradiation of 11-14 in benzene yielded substi tuted phenols. The plausible reaction pathways for the product formati on ate discussed.