(2E,6E)-2,6-Bis(4-methyl­benzyl­idene)cyclo­hex-3-en-1-one

The title compound, C₂₂H₂₀O, shows an approximately planar cyclo­hexenone ring [maximum deviation = 0.069 (4) Å], with a disordered position of the C=C bond [ratio = 0.71 (2)/0.29 (2)]. The benzene rings of the 4-methyl­benzyl­idene units, attached in the 2- and 6-positions to the cyclo­hexenone ring, are rotated in the same direction by 28.6 (4) and 22.4 (4)°, with respect to the mean plane of the cyclo­hexenone ring [fraction 0.71 (2); maximum deviation = 0.06 (3) Å]. In the crystal, mol­ecules are packed in the manner of a distorted hexa­gonal rod packing with their long axes all aligned along [201]. A number of C—H...π inter­actions stablize the crystal structure.

(4Z,6Z)-4,6-Bis(4-meth­oxy­benzyl­idene)-2,2-dimethyl-1,3-dioxan-5-one

The title compound, C₂₂H₂₂O₅, crystallizes with two independent mol­ecules in the asymmetric unit, both of which possess pseudo-C_s symmetry. The central 1,3-dioxanone rings have envelope conformations, with the C atom bearing the two methyl groups at the flap. The benzene rings of the meth­oxy­benzyl­idene units, attached in the 4- and 6-positions on the central 1,3-dioxanone rings, are tilted in the same direction with dihedral angles varying between 8.2 (1) and 18.1 (1)°. The crystal packing is influenced by π-stacking inter­actions of the parallel displaced type [centroid–centroid distance of 3.723 (1) Å for mol­ecule 1 and 3.884 (1) Å for mol­ecule 2, with ring slippages of 1.432 and 1.613 Å, respectively] and the T-shaped type, with the long mol­ecular axes all aligned along [010].

rac-3-[(3-Chloro­anilino)(4-chloro­phenyl)meth­yl]thian-4-one

In the title compound, C₁₈H₁₇Cl₂NOS, the thio­pyran­one ring adopts a chair conformation, with the substituent in the axial position. The dihedral angle between the two benzene rings is 89.43 (1)°. In the crystal, mol­ecules form inversion dimers through inter­molecular N—H...O hydrogen bonds [graph set R₂²(8)].

rac-3-[(Anilino)(naphthalen-2-yl)­methyl]thian-4-one

In the title compound, C₂₂H₂₁NOS, the thio­pyran­one ring adopts a chair-like conformation with the substituent in the axial position. The relative configuration of the racemic compound is 3R,7S according to the numbering scheme used in this publication. In the crystal packing, centrosymmetric dimers are built up via N—H...O hydrogen bonds, with graph set R₂²(8).