Some thermal and photo-reactions of benzo- and naphtho-furandiones (coumarandiones)

Abstract

New thermal reactions of benzo- and naphtho-furandiones with some nucleophiles are reported. This has led to the synthesis of 3-diazobenzofuranone and 1-diazonaphthofuranone. The photo-decarbonylation of 2,3-dihydrobenzofuran-2,3-dione (1a), the corresponding 6-methyl compound (1b), and 1,2-dihydronaphtho[2,1-b]furan-1,2-dione (5) has been studied. Our results suggest that the intermediate in the reaction is a keto-keten. This could be trapped by water, phenols, and more importantly by carboxylic acids to afford anhydrides.