Synthesis of Regioisomeric Functionalized Benzodifurans and Angelicins.

Arenofurans have important biological and pharmacological activities. Compared to benzofurans, the reports on the synthesis of benzodifurans are rather limited. Here, we report the synthesis of a linear and an angular 3,3′biscarboxymethylsubstituted benzodifuran and 4′carboxymethylsubstituted angelicins from phloroglucinol, using 4halomethylsubstituted dipyrones as key intermediates in the synthetic route. This strategy shows that the stability of a pyrone ring depends on the type of substituent at C4 and the conditions used. [ABSTRACT FROM AUTHOR]