3-Phenyl-4H-furo[3,2-C]chromen-4-one.

The crystal structure of the title compound, C(17)H(10)O(3), is the first example of a furocoumarin containing three fused rings. The tricyclic furocoumarin fragment is perfectly planar. The phenyl substituent forms a dihedral angle of 39.52 (8) degrees with the plane of the tricyclic system. The crystal packing involves centrosymmetric dimers interconnected by strong pi-interactions between their furo[3,2-c]coumarin fragments [at distances of 3.42 (4) A].