In the title compound, C17H16O4, the dihedral angle between the mean planes of the hy­droxy­phenyl and dimeth­oxy­phenyl rings is 5.9 (6)°. The mean plane of the prop-2-en-1-one group makes dihedral angles of 3.6 (0) and 2.6 (7)° with the hy­droxy­phenyl and dimeth­oxy­phenyl rings, respectively. An intra­molecular O—H⋯O hydrogen bond occurs. The crystal packing is stabilized by weak inter­molecular C—H⋯O contacts and π–π stacking inter­actions [centroid–centroid distance = 3.6571 (8) Å].

In the title compound, C15H11ClO2, the dihedral angle between the mean planes of the chloro­benzene and hy­droxy­benzene rings is 6.5 (6)°. The mean plane of the prop-2-en-1-one group makes an angle of 18.0 (1)° with the hy­droxy­phenyl ring and 11.5 (1)° with the chloro­phenyl ring. The crystal packing is stabilized by inter­molecular O—H⋯O hydrogen bonds, weak C—H⋯O, C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.7771 (7) and 3.6917 (7) Å].

In the title compound, C17H16O4, the dihedral angle between the mean planes of the hy­droxy­phenyl and dimeth­oxy­phenyl rings is 19.34 (7)°. The mean plane of the prop-2-en-1-one group, the active site in this mol­ecule, makes angles of 7.40 (8) and 13.25 (8)°, respectively, with the hy­droxy­phenyl and dimeth­oxy­phenyl rings. The crystal packing is stabilized by O—H⋯O hydrogen bonds, weak inter­molecular C—H⋯O and π–π stacking inter­actions [centroid–centroid distance = 3.7386 (9) Å].

The asymmetric unit of the title compound, C23H16O2, contains two independent mol­ecules in which the dihedral angles between the anthracene ring system and the benzene ring are 73.0 (3) and 73.3 (3)°. In both independent mol­ecules, the hy­droxy group is involved in an intra­molecular O—H⋯O hydrogen bond. The crystal packing is stabilized by π–π inter­actions [centroid–centroid distances = 3.6518 (9), 3.7070 (9) and 3.7632 (9) Å] and weak inter­molecular C—H⋯O hydrogen bonds.

In the title compound, C22H18O3, an intra­molecular O—H⋯O hydrogen bond stabilizes the mol­ecular structure, forming an S(6) ring motif. The central benzene ring forms a dihedral angle of 64.74 (5)° with the phenyl ring and a dihedral angle of 5.58 (5)° with the terminal benzene ring. In the crystal, mol­ecules are linked into columns along the a axis via inter­molecular C—H⋯O hydrogen bonds. C—H⋯π inter­actions involving the centroid of the hy­droxy-substituted benzene ring further stabilize the crystal structure.