Intra- and intermolecular photocyclization of vinylbenzo-1,4-quinones

摘要: The photochemical reactions of a variety vinylbenzo-1,4-quinones have been investigated. Irradiation benzene solution 2-methyl-5-(1-phenylvinyl)benzo-1,4-quinone affords quantitatively benzofuranol via intramolecular cyclization, while the styryl derivative gives novel dimer by way intermolecular (4 + 2) cycloaddition. In contrast to these two quinones, (2,2-diphenylvinyl) phenanthrene-1,4-quinone stilbene-like photocyclization. reaction paths intra- and are also discussed.