Facile total synthesis of xanthotoxol

Xanthotoxol, a biologically active linear furocoumarin, has been efficiently synthesized from 7-hydroxycoumarin in six steps. The key steps included two efficient rearrangements-Fries rearrangement and Claisen rearrangement-and a BaeyerVilliger oxidation process. The overall yield of xanthotoxol was 29%. This approach also provided a new strategy to furnish easily furocoumarins with a hydroxyl group in the framework.