Photochemical reactions of methyl 3-(o-alkylphenyl)-2, 2-dimethyl-3-oxopropanoates in hexane gave only the corresponding benzocyclobutenols. However, when irradiation was carried out in methanol, 3-oxonaphthalenones were produced together with the benzocyclobutenols. The ratio of benzocyclobutenol to naphthalenone depends on the bulkiness of the alkyl group in the ortho position. Intermediary 1, 4-diradicals or dienols ...
