Reaction of Furanopyrones with aluminium chloride in benzene

Abstract

The product obtained by the reaction of angelicin (II) with aluminium chloride in benzene has been formulated as 7-hydroxy-8-(β,β-diphenylethyl)coumarin (IV). 7-Methoxy-8-(α,α-diphenylethyl) coumarin (IX) has been synthesized by the condensation of ethyl propiolate with 2-hydroxy-6-methoxy-l-(β,β-diphenylethyl)benzene (XV ) in the presence of ZnCl₂. IX has been shown to be identical with the methyl ether of (IV). Psoralen (I) and chalepensin (V) are shown to give the furan opened benzene addition products 7-hydroxy-6-(β,β-diphenylethyl)coumarhi (III) and 7-hydroxy-8-(β,β-diphenylethyl)coumarin (IV) respectively. Reaction of karanjin (XVII) with aluminium chloride in benzene gives 3,7-dihydroxy-8-(β,β-diphenylethyl)-fiavone (XVIII).