Reaction of Furanocoumarins with aluminium chloride in benzene

Abstract

The reaction of A1C1₃ and benzene on the naturally occurring linear furanocoumarin chalepensin (II) is shown to give crystalline benzene addition product, C₂₄H₃₂0₂, m.p. 191°. On the basis of NMR and mass spectra it has been formulated as (III). Similar benzene addition products from psoralen and angelicin earlier assigned the structures IV and V respectively [Proc. Indian Acad. Sci., 16A (1942), 151] have now been shown on the basis of NMR and mass spectra to have the structures (VI) and (VII) respectively.