Acid-Catalyzed Cyclization of 2,3-Dibenzylidenesuccinates: Synthesis of Lignans (±)-Cagayanin and (±)-Galbulin

Acid-catalyzed cyclizations of E,E-dibenzylidenesuccinate esters have been developed as an efficient synthetic route to 1-aryl-1,2-dihydronaphthalenes. This reaction has been used in the synthesis of the naturally occurring lignans (±)-cagayanin and (±)-galbulin.