New synthetic approaches to 4,8-dimethyl-5'-(N-pyridiniummethyl)-4',5'-dihy
dropsoralens and 4,8-dimethyl-5'-(N-aminomethyl)-4',5'-dihydropsoralens are
described. The 5'-halomethyl-4',5'-dihydropsoralen precursors are formed b
y electrophilic ring closures of 4,8-dimethyl-6-allyl-7-hydroxycoumarin. Th
e ring-closure reactions may also be applied to the synthesis of 5'-halomet
hyl-4-methyl-4',5'-dihydroangelicins. The compounds are potential therapeut
ic agents for improved psoralen ultraviolet A radiation treatment.