Pomiferin.

The crystal structure of pomiferin, 3-(3,4-dihydroxyphenyl)-5-hydroxy-8,8-dimethyl-6-(3-methylbut-2-enyl)-4H,8H-pyrano[2,3-h]chromen-4-one, C(25)H(24)O(6), has been determined. The benzopyranone ring system is nearly planar and the dihedral angle between the phenyl ring and the benzopyranone moiety is 40.85 (4) degrees. The crystal structure is stabilized by a one-dimensional chain of inter- and intramolecular O-H...O hydrogen bonds, with O...O distances in the range 2.5546 (15)-2.7999 (16) A.