Synthesis of benzofuranoid systems. V. Alternative total synthesis of cyperaquinones

Abstract

An alternative route to unsymmetrically substituted benzo[1,2-b:5,4-b']difuranquinones starting from pyrogallol and proceeding via the linear furocoumarin nucleus has been used to synthesize the three naturally occurring compounds cyperaquinone (1), conicaquinone (2) and demethylcyperaquinone (3).