[2-(4-Chloro­phen­yl)-5-phenyl­oxolan-3-yl](cyclo­penten­yl)methanone

In the title compound, C₂₂H₂₁ClO₂, the oxolane ring adopts a twisted conformation. The dihedral angles between the mean plane of the oxolane ring and the mean planes of the 4-chloro­phenyl, phenyl and cyclo­pentenyl rings are 71.81 (18), 76.9 (18) and 82.08 (18)°, respectively.

(E)-2,2′-[3-(2-Nitro­phen­yl)prop-2-ene-1,1-di­yl]bis­(3-hy­droxy­cyclo­hex-2-en-1-one)

In the title compound, C₂₁H₂₁NO₆, each of the cyclo­hexenone rings adopts a half-chair conformation. Each of the pairs of hy­droxy and carbonyl O atoms are oriented to allow for the formation of intra­molecular O—H...O hydrogen bonds, which are typical of xanthene derivatives.

9-[(E)-2-(2-Meth­oxy­phen­yl)ethen­yl]-3,4,5,6,7,9-hexa­hydro-2H-xanthene-1,8-dione

In the title compound, C₂₂H₂₂O₄, the two cyclo­hexenone rings adopt half-chair conformations, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms by 0.142 (2) and 0.287 (2)Å, respectively. In the crystal, weak C—H...O hydrogen bonds link mol­ecules into chains running parallel to the a axis.

(E)-9-(4-Chloro­styr­yl)-3,4,5,6,7,9-hexa­hydro-2H-xanthene-1,8-dione

In the title compound, C₂₁H₁₉ClO₃, the two cyclo­hexenone rings adopt half-chair conformations, whereas the pyran ring adopts a boat conformation. The 4-chloro­phenyl ring is almost perpendicular to the plane through the four C atoms of the pyran ring [dihedral angle = 87.97 (6)°]. In the crystal, weak C—H...O hydrogen bonds link the mol­ecules into a chain parallel to the a-axis.

(E)-3,3,6,6-Tetra­methyl-9-(2-nitro­styr­yl)-3,4,5,6,7,9-hexa­hydro-1H-xanthene-1,8(2H)-dione

In the title compound, C₂₅H₂₇NO₅, each of the cyclo­hexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms. In the crystal, weak C—H...O hydrogen bonds link mol­ecules into chains parallel to the c axis.

2,2′-[(E)-3-(4-Nitro­phen­yl)prop-2-ene-1,1-di­yl]bis­(3-hy­droxy-5,5-dimethyl­cyclo­hex-2-en-1-one)

In the title compound, C₂₅H₂₉NO₆, each of the cyclo­hexenone rings adopts a half-chair conformation. The hy­droxy and carbonyl O atoms face each other and are oriented to allow for the formation of two intra­molecular O—H...O hydrogen bonds. In the crystal, weak C—H...O hydrogen bonds are formed between molecules, generating a two-dimensional supramolecular structure.

(E)-N-(3,3-Diphenyl­allyl­idene)-3-nitro­aniline

In the title compound, C₂₁H₁₆N₂O₂, the 3-nitro­phenyl and two phenyl rings are twisted from the mean plane of the enimino fragment by 44.4 (1), 37.2 (1) and 74.1 (1)°, respectively. The crystal packing exhibits no classical inter­molecular contacts.

(E)-N-(3,3-Diphenyl­allyl­idene)-4-nitro­aniline

In the title compound, C₂₁H₁₆N₂O₂, the dihedral angles between the mean planes of the 4-nitro­phenyl ring and the two phenyl rings are 57.3 (5) and 16.8 (6)°. The imine group displays a C-C-N-C torsion angle of -24.9 (3)°.