(E)-1-(2-Hydr­oxy-3,4-dimethoxy­phen­yl)-3-(4-hydroxy­phen­yl)prop-2-en-1-one

The title compound, C₁₇H₁₆O₅, crystallizes with two independent mol­ecules in the asymmetric unit. These are oriented approximately orthogonal to one another. The keto group adopts an s-cis conformation; the six-membered ring formed by the O—H...O hydrogen bond and the adjacent benzene ring are approximately coplanar. In addition to an intra­molecular O—H...O hydrogen bond, inter­molecular O—H...O inter­actions link adjacent mol­ecules into chains.

6-(2,4-Dichloro­phen­oxy)­dibenzo­[d,f]­[1,3,2]­dioxaphosphepine-6-sulfide

In the title compound, C₁₈H₁₁Cl₂O₃PS, the seven-membered phosphepine ring exhibits a distorted-boat conformation, with the phosphor­yl sulfide group axial and the dichloro­phen­oxy group equatorial. Fusion of the phosphepine ring to the biphen­yl system causes strain, as evidenced by both widening and compression of the endocyclic angles in the heterocyclic ring. The P=S bond length is 1.8939 (12) Å and the planar dichloro­phen­yl ring is oriented at an angle of 28.70 (6)° to the phosphepine ring.

5-Hydr­oxy-7,8,2′-trimethoxy­flavone

Mol­ecules of the title compound, C₁₈H₁₆O₆, are almost planar. The dihedral angle between the benzopyran system and the benzene ring is 3.36 (5)°. In addition to an intra­molecular O—H...O hydrogen bond, mol­ecules are connected by weak inter­molecular C—H...O hydrogen bonds to form a two-dimensional framework.

5,2′-Dihydr­oxy-7-methoxy­flavanone

The γ-pyran­one ring of the title mol­ecule, C₁₆H₁₄O₅, adopts an envelope conformation. The crystal packing is stabilized by O—H...O and C—H...O hydrogen bonding.