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 Baeyer–Villiger 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. [ABSTRACT FROM AUTHOR]