In the title mol-ecule, C(13)H(16)O(6), the cyclo-hexa-1,4-diene ring adopts a flat boat conformation (r.m.s. deviation from planarity = 0.060 Å) and the five-membered tetra-hydro-furan ring adopts an envelope conformation with the carboxyl group-substituted C atom as the flap. The dihedral angle at the spiro junction is 89.1 (1)°. In the crystal, mol-ecules are linked through weak C-H⋯O and va...

In the title compound, C39H58O4, the steroid rings A and C adopt a chair conformation, while ring B adopts a half-chair conformation, and ring D has an envelope conformation, with the methyl-substituted C atom as the flap. In the crystal, mol-ecules pack within layers parallel to (100), with their long axis parallel to the [101] direction. Adjacent layers are linked via C-H⋯O hydrogen bonds and...

In the pregnene fragment of the title compound, C27H38ClN, the three six-membered rings exhibit chair conformations and the five-membered ring has a distorted envelope form with the fused C atom not bearing a methyl group as the flap atom. The amino group is involved in the formation of an intra-molecular N-H⋯Cl hydrogen bond. The crystal packing exhibits no short inter-molecular contacts.

In the title compound, C(11)H(10)O(3), the benzodioxole ring adopts a flattened [puckering parameters: q(2) = 0.107 (2) Å, ϕ(2) = 160 (1)°] envelope conformation with the methylene C atom as the flap. The crystal packing features chains, parallel to the c axis, composed of dimers connected by weak C-H-O hydrogen bonds and extending in layers in the bc plane.

The absolute structure of the chiral asymmetric indole precursor title compound, C11H13NO3S, was confirmed by refinement of the Flack and Hooft parameters and is that expected based on the starting materials for the synthesis. The phenyl group subtends a dihedral angle of 56.40 (5)° with the mean plane of the oxazolidinone ring, which adopts an envelope conformation, with the C atom bearing the...

In the title compound, C(11)H(10)Br(2)O(2), the cyclo-pentene ring fused to the benzene ring adopts an envelope conformation, with the C atom attached to the Br atom as the flap. The crystal structure does not exhibit any classical hydrogen bonds. The mol-ecular packing is stabilized by van der Waals forces and π-π stacking inter-actions with a centroid-centroid distance of 3.811 (4) Å.

In the title compound, C(27)H(25)NO, the piperidine ring adopts an envelope conformation with the N atom at the flap position. The two benzylidene-benzene rings are oriented at a dihedral angle of 8.5 (1)°. In the crystal, the mol-ecules are linked into centrosymmetric dimers by pairs of inter-molecular C-H⋯O hydrogen bonds. The dimers are connected via C-H⋯π inter-actions involving the phenyl ...

In the title compound, C13H10O3, the pyran-one and benzene rings are almost coplanar, making a dihedral angle of 1.9 (1)°. The cyclo-hexenone ring adopts an envelope conformation, with a methyl-ene C atom located at the flap and displaced by 0.639 (3) Å from the mean plane of the other five atoms. In the crystal, pairs of weak C-H⋯π inter-actions occur between inversion-related mol-ecules.

In the zwitterionic title compound, C(9)H(13)NO(2)S, the pyrrolidine heterocycle adopts an envelope conformation (with the C atom in the 7-position as the flap). The negative charge is delocalized over the two carbonyl groups and the C atom connecting them. The positive charge is located on the S atom. Two inter-molecular C-H⋯O inter-actions are observed. The molecular geometry at the S atom is...

The asymmetric unit of the title compound, C54H64O12S4, consists of one half of the mol-ecule, which is located on an inversion centre. The heterocyclic six-membered ring adopts a distorted envelope conformation with the spiro C atom as the flap. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds with an R (2) 2(14) motif, forming a chain along the b-axis direction.