nine furothiocoumarins corresponding to psoralen , 8-methylpsoralen , 3-carbethoxy-8-methylpsoralen , 8-methoxypsoralen , pseudopsoralen , angelicin , isopseudopsoralen , allopsoralen and pseudoisopsoralen were synthesized by treating furocoumarins with phosphorus pentasulfide .
C0016072
psoralen
C0016859
furocoumarins