ChemInform Abstract: Synthesis of New Dibenzofuran Derivatives via Diels-Alder Reaction of Euparin with Activated Acetylenic Esters

An efficient synthesis of novel dibenzofuran derivatives has been achieved via the Diels–Alder reaction of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone, named euparin, with acetylenic diesters and propiolates in the presence of triphenylphosphine as a catalyst in toluene. All products were obtained by recrystallization from ethanol and did not require column chromatography.