Crystal structure of a photobiologically active furan­ocoumarin from Artemisia reticulata

The title furan­ocoumarin, C14H12O4 [systematic name: 9-hy­droxy-2-(prop-1-en-2-yl)-2,3-di­hydro-7H-furo[3,2-g]chromen-7-one], crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. The two mol­ecules differ essentially in the orientation of the propenyl group with respect to the mean plane of the furan­ocoumarin moiety; the O—C(H)—C=C torsion angle is 122.2 (7)° in mol­ecule A and −10.8 (11)° in mol­ecule B. In the crystal, the A and B mol­ecules are linked via O—H⋯O hydrogen bonds, forming zigzag –A–B–A–B– chains propagating along [001]. The chains are reinforced by bifurcated C—H⋯(O,O) hydrogen bonds, forming ribbons which are linked via C—H⋯π and π–π inter­actions [inter­centroid distance = 3.602 (2) Å], forming a three-dimensional structure.