8,12-Dioxa-1,7,10(1,2)-tribenzenacyclo­dodeca­phane-2,5-dien-4-one

In the title compound, C₂₅H₂₀O₃, two of the benzene rings are almost perpendicular to each other, with a dihedral angle of 88.1 (1)°. The mol­ecular packing is stabilized by inter­molecular C—H...O and π–π inter­actions, in addition to van der Waals forces.

2′-Benzo­yl-1′-(4-chloro­phen­yl)-5′,6′,7′,7a′-tetra­hydro­spiro­[indan-2,3′(2′H)-1H-pyrrolizine]-1,3-dione

The title compound, C₂₈H₂₂ClNO₃, has two crystallographically independent mol­ecules in the asymmetric unit. The pyrrolidine ring (A) of the pyrrolizine system adopts an envelope conformation in both mol­ecules, whereas the other five-membered ring (B) adopts an envelope conformation in one mol­ecule and a twist conformation in the other. The mol­ecular packing is stabilized by inter­molecular C—H...O, C—H...π and π–π inter­actions.

1-(p-Bromo­phen­yl)-5-p-tosyl­perhydro­pyrrolo[3,4-b]pyrrole

In the title compound, C₁₉H₂₁BrN₂O₂S, the fused pyrrolidine rings adopt envelope conformations. The mol­ecular packing is stabilized by weak inter­molecular C—H...O inter­actions and van der Waals forces.

Hydrogen bonding in 1′-nitro-2′-phenyl-2′,3′,4′,5′,6′,7′-hexa­hydro-1H-indole-3-spiro-3′-1′H-pyrrolizidin-2(3H)-one: mol­ecular chains built from alternating (18) and (8) rings

In the title cyclo­adduct, C₂₀H₁₉N₃O₃, the mol­ecules form centrosymmetric dimers linked by N—H...O hydrogen bonds, forming an R₂²(8) ring. The overall conformation of the pyrrolizidine nucleus is folded about the bridging bond.

1′-Methyl-4′,5-diphenyl-5,6,7,8,9,10-hexa­hydro-1,3-cyclo­hepta­pyrimidino[2,3-b]thia­zole-2-spiro-3′-pyrrolidine-2′-spiro-3′′-1H-indole-2′′,3(2H,3′′H)-dione

The pyrrolidine ring of the title compound, C₃₄H₃₂N₄O₂S, adopts an envelope conformation. The packing is stabilized by inter­molecular C—H...O and N—H...N inter­actions.

4′-(4-Methyl­phen­yl)-3′-nitro­spiro­[1H-indole-3,2′-pyrrolidin]-2-one

In the title compound, C₁₉H₁₉N₃O₃, the oxindole residue and the 4-methyl­phenyl ring are almost perpendicular to the pyrrolidine ring. The pyrrolidine ring adopts an envelope conformation. The mol­ecular packing is stabilized by N—H...O hydrogen bonds and C—H...O inter­actions, in addition to van der Waals forces.