A Synthesis of the Lichen Diphenyl Ether Epiphorellic Acid 1

Abstract

The lichen diphenyl ether epiphorellic acid 1 [6-hydroxy-3-(5'-hydroxy-2'-methoxycarbonyl- 3'-pentylphenoxy)-4-methoxy-2-pentylbenzoic acid] (5) has been prepared by unambiguous synthesis. The synthesis employed a biomimetic -type approach which envolved a Smiles rearrangement of a precursor meta- depside in the key step.