SYNTHESIS OF BENZOFURANOFURAN DERIVATIVES: MODEL OF NATURAL PRODUCTS

Abstract

Several benzofuranofuran derivatives were synthesized employing intramolecular cycloaddition reactions of ketenes with alkenes. (Alkenyloxy)ketenes, prepared from the tosylate by treatment with triethylamine, easily undergo intramolecular [2 + 2] cycloaddition to give tricyclic benzocyclobutafuranones. Baeyer-Villiger oxidation of the cycloadducts gives benzofurano-furanones, which are closely related to natural products with anticoagulant and antimalarial properties.

ACKNOWLEDGMENTS

The authors wish to thank to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and to Coordenadoria de Aperfeiçoamento de Pessoal do Ensino Superior (CAPES) for financial support.