Novel synthesis of dihydroxanthyletin and dihydroseselin derivatives

Article abstract of DOI:10.1002/jhet.5570270433

In a one-step alkylation, ring-closure 7-hydroxycoumarins are condensed in acid media with allyl and homoallyl halides or alcohols to linear 6,7-dihydro-2H,8H-benzo[1,2-b:5,4-b']dipyran-2-ones. If both carbon-6 and carbon-8 are unsubstituted in the original coumarin, cyclization to angular isomers 9,10-dihydro-2H,8H-benzo[1,2-b:3,4-b']dipyran-2- ones competes. These compounds are higher ring homologs of psoralens and angelicins commonly employed in phototherapy of skin disorders.