The diphenyl ether epiphorellic acid 3 [6-hydroxy-3-(5′-hydroxy-2′-methoxycarbonyl-3′-propylphenoxy)-4-methoxy-2-pentylbenzoic acid] (3) has been prepared by unambiguous synthesis, and has been detected in the lichen Coelopogon abraxas by chromatographic and spectroscopic comparisons.