Hydroxyquinone annelation

Hydroxyquinone annelation. The lid silyl ether 3 to provide the adduct 4. Con results in 6, which undergoes cyclizatioa a as the methyl ether 7. This quinooe aam vinylogous silyl ether. 

Senboku, H., Kajizuka, Y., Kobayashi, K., Tokuda, M., and Suginome, H., Photoinduced molecular transformations. 160. Furan annelation of 2-hydroxynaphthoquinone involving photochemical addition and radical fragmentation xeclusion of the intermediacy of [2-1-2] cycloadduct in a one-pot formation of furanoquinones by the regioselective 3-1-2 photoaddition of hydroxyquinones with alkenes. Heterocycles, 44, 341,1997. 

---