3′-[Hy­droxy(4-oxo-4H-chromen-3-yl)meth­yl]-2-oxospiro­[indoline-3,2′-pyrrolidine]-3′-carbonitrile

In the title compound, C₂₃H₁₉N₃O₄, the pyran ring adopts a half-chair conformation, while the pyrrolidine (with a C atom as the flap atom) and the five-membered ring in the indoline (with a C atom as the flap atom) ring system adopt slight envelope conformations. The pyrrolidine ring makes dihedral angles of 83.3 (1) and 60.4 (1)° with the mean plane through all non-H atoms of the indoline and chromene ring systems, respectively. In the crystal, mol­ecules are connected by two unique N—H...O and O—H...O hydrogen-bonding inter­actions, which form centrosymmetric patterns described by graph-set motifs R₂²(18) and R₂²(14). These two motifs combine to form a hydrogen-bonded chain which propagates in the a-axis direction. The crystal structure is also stablized by C—H...O inter­actions and by aromatic π–π stacking inter­actions between the pyran and benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.755 (1) Å and slippage = 1.371 (2) Å].

(E)-2-({2-[(E)-(Hy­droxy­imino)­meth­yl]phen­oxy}meth­yl)-3-o-tolyl­acrylonitrile

In the title compound, C₁₈H₁₆N₂O₂, the dihedral angle between the mean planes through the two benzene rings is 56.8 (6)°. The enoate group assumes an extended conformation. The hy­droxy­ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane being 0.047 (1) Å for the hy­droxy­imino O atom. In the crystal, the mol­ecules are linked into cyclic centrosymmetric dimers with R₂²(6) motifs via O—H...N hydrogen bonds.

(E)-Methyl 2-({2-eth­oxy-6-[(E)-(hy­droxy­imino)­meth­yl]phen­oxy}meth­yl)-3-phenyl­acrylate

In the title compound, C₂₀H₂₁NO₅, the dihedral angle between the mean planes through the two rings is 47.1 (8)°. The enoate group assumes an extended conformation. The hy­droxy­ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane being 0.061 (1) Å for the O atom. In the crystal, mol­ecules are linked into cyclic centrosymmetric dimers with an R₂²(6) motif via pairs of O—H...N hydrogen bonds. Inter­molecular C—H...O hydrogen bonds form a C(8) chain along the b axis. The crystal packing is further stabilized by C—H...π inter­actions.

Methyl (E)-2-({2-[(E)-(hy­droxy­imino)­meth­yl]phen­oxy}meth­yl)-3-(4-methyl­phen­yl)acrylate

In the title compound, C₁₉H₁₉NO₄, the dihedral angle between the mean planes through the benzene rings is 82.18 (7)°. The C=N double bond is trans-configured. The mol­ecules are linked into centrosymmetric dimers via pairs of O—H...N hydrogen bonds with the motif R₂²(6). The crystal packing also features C—H...O inter­actions. The methyl group attached to one of the aromatic rings is disordered over two almost equally occupied positions [occpancy ratio = 0.51 (4):0.49 (4)].

(3,4-Dimeth­oxy­phen­yl)[2-(thio­phen-2-ylcarbon­yl)phen­yl]methanone

In the title compound, C₂₀H₁₆O₄S, the thiophene ring makes dihedral angles of 72.9 (2) and 60.5 (2)°, respectively, with the dimethoxy benzene and phenyl rings. In the crystal, C—H...O hydrogen bonds link the mol­ecules into a C(9) chain along the b axis. The S and C atoms of the thio­phene ring are disordered over two sets of sites [site occupancies = 0.675 (3) and 0.325 (3)]. A short inter­molecular S...O contact [3.084 (2) Å] is observed in the crystal structure, which also features C—H...π inter­actions.

Methyl (3S,3′R)-1-methyl-2,2′′-dioxo-1′,2′,3′,5′,6′,7′,8′,8a′-octa­hydro­dispiro­[indoline-3,2′-indolizine-3′,3′′-indoline]-1′-carboxyl­ate

In the title compound, C₂₅H₂₅N₃O₄, the central pyrrolidine ring and the two pyrrolidine rings adopt twisted conformations, whereas the piperidine ring in the octa­hydro­indolizine fused ring system adopts a chair conformation. The indoline ring systems are almost perpendicular with respect to the mean plane of the octa­hydro­indolizine ring system, making dihedral angles of 84.4 (5) and 79.4 (5)°. The acetate group attached to the octa­hydro­indolizine ring system assumes an extended conformation. In the crystal, N—H...O hydrogen bonds result in the formation of a helical C(7) chain running parallel to [101]. The crystal packing features C—H...O hydrogen bonds and C—H...π inter­actions.

Methyl (3R*,3′S*)-1′,1′′-dimethyl-2,2′′-dioxodispiro­[indoline-3,2′-pyrrolidine-3′,3′′-indoline]-4′-carboxyl­ate

In the title compound, C₂₂H₂₁N₃O₄, the central pyrrolidine ring adopts an envelope conformation with the N atom in the flap position. The indoline ring systems are almost perpendic­ular to the mean plane of the pyrrolidine ring, making dihedral angles of 86.4 (8) and 83.1 (8)°. The acetate group attached to the pyrrolidine ring assumes an extended conformation. In thecrystal, N—H...O hydrogen bonds result in the formation of a C(7) chain running along [100]. The crystal packing also features π–π inter­actions [centroid–centroid distance = 3.2032 (11) Å].

(2-Benzoyl­phen­yl)(naphthalen-1-yl)methanone

In the title compound, C₂₄H₁₆O₂, the naphthalene ring system makes dihedral angles of 78.5 (6) and 65.5 (7)° with the terminal and central benzene rings, respectively. The dihedral angle between the benzene rings is 74.5 (8)°. In the crystal, neighbouring molecules are interlinked through two C—H...π interactions, which construct a two-dimensional supramolecular framework extending infinitely along (010).