The coumarins of Halfordia scleroxyla F. Muell

Abstract

The bark of Halfordia scleroxyla F. Muell. has been found to contain the known coumarin xanthoxyletin and two new isomeric furoooumarins of formula C₁₄H₁₂O₆ which have been named halfordin and isohalfordin. By degradation, halfordin is shown to possess structure (Ia) or (Ib) and isohalfordin structure (Va) or (Vb). This constitutes the first recorded isolation of the 3-methoxyfurocoumarin system from natural sources.