The asymmetric unit of the title compound, C(27)H(46), contains two crytallographically independent cholest-5-ene mol-ecules (A and B). In each mol-ecule, the three six-membered rings are all in chair conformations, while the five-membered ring is in a twist conformation. The terminal isopropyl group of mol-ecule A has a (-)-gauche conformation, whereas that of mol-ecule B has a (+)-gauche conf...

In the title compound, C(29)H(27)N(3)O(5), a dibenz[b,f][1,4]oxazepine derivative, the cyclo-hexane ring adopts a chair conformation, the oxazepine seven-membered ring has a twist-boat conformation, and the piperidin-2-one ring assumes a flattened boat conformation. Inter-molecular N-H⋯O hydrogen bonding between imino and nitro groups links two mol-ecules into a centrosymmetric dimer.

In the title compound, C(28)H(35)N(3)O(4), the piperidine ring adopts a boat conformation while the piperazine ring adopts a chair conformation with an equatorial orientation of the phenyl groups. The dihedral angle between the mean planes of the benzene rings is 74.14 (8)°. The mol-ecular conformation is stabilized by a weak intra-molecular C-H⋯N inter-action and the crystal packing is stabili...

In the title compound, C(20)H(28)O(4), a diterpenoid isolated from the roots of Premna obtusifolia (Verbenaceae), the five-membered ring is in a half-chair conformation. One six-membered ring exists in a twisted-boat conformation while the other is in half-boat conformation. The crystal packing is stabilized by inter-molecular O-H⋯O and weak C-H⋯O inter-actions, generating (001) sheets.

Monohydrochlorides of cis-2,5-diphenylpiperazine assume a chair conformation, while the corresponding dihydrochlorides assume a boat form regardless of the substituent(s) at the nitrogen atom.

In the title compound, C(20)H(22)O(5), an S(6) ring motif is formed by an intra-molecular C-H⋯O hydrogen bond, which contributes to the stabilization of the mol-ecule. In the xanthene system, the cyclo-hexane ring adopts a chair conformation, the cyclo-hexene ring adopts a half-boat conformation and the tetra-hydro-pyran ring adopts a half-chair conformation. The mean plane of the four essentia...

In the title compound, C37H32F2N2O2, the central six-membered piperidine ring adopts a twisted half-chair conformation, with the N and methyl-ene C atoms deviating by -0.2875 (16) and 0.4965 (15) Å, respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octa-hydro-indolizine ring is in a half-chair conformation. The five-membered pyrrole ring adopts a...

In the crystal structure of the title compound, C(43)H(46)NO(13)·0.5H(2)O, the mol-ecule assumes a U-shaped conformation, the terminal benzene rings being approximately parallel and partially overlapped with each other. The mol-ecule contains eight alicyclic and heterocyclic rings. The cyclo-hexane rings adopt chair conformations, the other three six-membered carbocyclic rings form a bicyclo-[2...

The title quassinoid compound, C(20)H(24)O(9)·CH(3)OH·2H(2)O, is a natural eurycomanone isolated from the roots of Eurycoma longifolia. The mol-ecules contain a fused five-ring system, with one tetra-hydro-furan ring adopting an envelope conformation, one tetra-hydro-pyran-2-one ring in a screw boat conformation, one cyclo-hexenone ring in a half-chair conformation and two cyclo-hexane rings in...

In the title compound, C(39)H(38)N(2)O(4), the pyridinone ring adopts a twisted half-chair conformation with the N atom deviating by 0.3304 (1) and with the methyl-ene C atom adjacent to the octa-hydro-indolizine unit deviating by 0.444 (3) Å from the mean plane defined by the other four atoms. In the octa-hydro-indolizine system, the pyrrolidine ring exhibits an envelope conformation, with the...