Photochemistry of Substituted 4,4-Dimethoxy-2,5-Cyclohexadienones
摘要:
Abstract4,4‐Dimethoxy‐2,5‐cyclohexadienones 9–14 were prepared from the corresponding hydroquinone monomethyl ethers by oxidation with thallium trinitrate 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 afforded 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 substituted phenols. The plausible reaction pathways for the product formation are discussed.
The dienone-phenolrearrangement of 4,4-disubstituted cyclohexadienones catalyzed by Re2O7 has been described. Multi-substituted phenols can be efficiently obtained in good to excellent yields by employing this catalytic protocol.
已经描述了由Re 2 O 7催化的4,4-二取代的环己二酮的二烯酮-苯酚重排。通过使用该催化方案,可以以良好或优异的收率有效地获得多取代的苯酚。