International Union of Crystallography, Acta Crystallographica Section E: Structure Reports Online, 9(69), p. o1456-o1457, 2013
DOI: 10.1107/s1600536813021223
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The title xanthone (systematic name: 3,6,11-trihydroxy-1,1-dimethyl-2,3-dihydrochromeno[2,3-f]chromen-7-one monohydrate), known as pruniflorone N, crystallized as a monohydrate, C18H16O6·H2O. The three ring systems of the xanthone skeleton are approximately coplanar, with an r.m.s. deviation of 0.0270 (1) Å from the plane through the 14 non-H atoms. The O atoms of the two hydroxy substituents on the benzene rings also lie close to this plane, with deviations of 0.019 (1) and 0.070 (1) Å. The 2′-hydroxy-4′,4′-dimethylpyran ring is disordered over two positions with a 0.798 (3):0.202 (3) site-occupancy ratio. An intramolecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the xanthone and water molecules are linked into a three-dimensional network by O—H⋯O hydrogen bonds and weak C—H⋯O interactions. π–π interactions, with centroid–centroid distances of 3.5982 (7), 3.6081 (7) and 3.6456 (7) Å, are also observed.