Synthesis of Bioactive Natural Polymethoxyflavones and Their Vinyl Ether Derivatives

Bioactive natural polymethoxyflavones 1-6 and their vinyl ether derivatives 7-15 were synthesized by bromination,aromatic nucleophilic substitution,methylation,benzyl protection,Friedel-Crafts acetylation,aldol condensation,cyclization,DDQ dehydrogenation,regioselective demethylation,debenzylation and O-prenylation or O-farnesylation with resorcinol and appropriate substituted benzaldehydes as starting materials.Among them,compounds 7-15 are new compounds.Natural products 2-4 were firstly total synthesized.The syntheses of compounds 1,5 and 6 were efficiently improved by the new synthetic routes.The structures of all synthetic compounds were confirmed by NMR,IR spectra and MS.