In the title compound, C23H34O4, the C/D and D/E rings are trans fused and the A/B ring possesses an anti fusion. The two cyclohexane rings adopt a chair conformation while the cyclohexene ring exhibits a half-chair conformation. The cyclopentane ring displays an envelope conformation with the C atom bearing the methyl group as the flap. In the crystal, the molecules are linked by O—H⋯O hydrogen bonds, forming chains along the b axis.
The title dammarane triterpenoid, C30H50O4, assigned the name chrysura, was isolated from an ethyl acetate extract of Walsura chrysogyne leaves (Meliaceae). It has 20S*,24S* relative stereochemistry and an oxepanone ring with two methyl groups at position 4. The two cyclohexane rings adopt chair conformations. The cyclopentane and tetrahydrofuran rings have envelope conformations; their mean planes make a dihedral angle of 13.1 (3)°, indicating that the rings are only slightly tilted with respect to each other. There is an intramolecular C—H⋯O hydrogen bond in the molecule, which forms S(6) and S(7) ring motifs. In the crystal, molecules are linked via O—H⋯O and C—H⋯O hydrogen bonds, forming chains propagating along  which stack along the b-axis direction.
The asymmetric unit of the title compound, C32H51N3O3, consists of two crystallographically independent molecules, A and B; the 2-methylpentane group of molecule A and the propane group of molecule B are each disordered over two sets of sites, with refined site-occupancies of 0.825 (5):0.175 (5) and 0.630 (18):0.370 (18), respectively. In both molecules, the three cyclohexane rings in the steroid fused ring systems adopt chair conformations while the cyclopentane rings adopt envelope and twist conformations in molecules A and B, respectively. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds link the two independent molecules together, generating R
1(7) and R
2(8) ring motifs.
The asymmetric unit of the title compound, C30H48ClN3O, contains two molecules, A and B. In both molecules, the three cyclohexane rings in the steroid fused ring systems adopt chair conformations, while the cyclopentane rings adopt envelope and twist conformations in molecules A and B, respectively. In molecule B, the cyano group is disordered over two orientations with refined site-occupancies of 0.593 (8) and 0.407 (8). An intramolecular C—H⋯N interaction forms an S(10) ring in both molecules. In the crystal, molecules are linked by N—H⋯O, C—H⋯O and C—H⋯N interactions, resulting is chains propagating along the a-axis direction.
In the decahydrophenanthrenone ring system of the title compound, C27H44O, the two cyclohexane rings adopt chair conformations, whereas the cyclohexene ring adopts an envelope conformation. The cyclopentane ring is twisted. In the crystal structure, molecules are stacked along the a axis, but no significant intermolecular interactions are observed.
The title compound, C28H44O4·0.56H2O, is a co-crystal of methyl isoeichlerialactone monohydrate as the major component and methyl isoeichlerialactone as the minor component in a 0.55778 (3):0.44222 (3) ratio. The conformations of both components are identical except for that of the –COOCH3 group of the methyl propanoate side chain on the cyclohexane ring which is positionally disordered over two orientations. The molecule of methyl isoeichlerialactone has three fused rings and all rings are trans-fused. The two cyclohexane rings are in standard chair conformations and the cyclopentane ring adopts an envelope conformation. In the crystal, weak C—H⋯O interactions link methyl isoeichlerialactone molecules into screw chains along . The crystal structure is further stabilized by O—H⋯O hydrogen bonds and weak C—H⋯O interactions.
The title compound, C30H50O5, was isolated from the bark of Aglaia smithii. There are two independent molecules in the asymmetric unit that differ in the orientation of the isopropenyl group attached to the cyclohexane ring. The cyclohexane rings in both molecules adopt chair conformations, whereas the cyclopentane and tetrahydrofuran rings adopt envelope conformations. The independent molecules are linked into a layer parallel to (010) by O—H⋯O hydrogen bonds.
The asymmetric unit of the title compound, C27H45ClO, consists of two crystallographically independent molecules. In both molecules, the three cyclohexane rings in the steroid fused-ring systems adopt chair conformations, while the cyclopentane ring adopts a half-chair conformation in one molecule and an envelope conformation in the other. In the crystal, the molecules are linked into a two-dimensional network by weak C—H⋯O hydrogen bonds. The crystal studied is a nonmerohedral twin with a refined ratio of twin components of 0.264 (3):0.736 (3).
In the title compound, C30H26N2O3, the two pyrrolidine rings adopt twisted and envelope conformations, whereas the cyclopentane ring adopts an envelope conformation. The least-squares planes through the pyrrolidine rings form a dihedral angle of 41.72 (10)°. The molecular structure is stabilized by an intramolecular O—H⋯N hydrogen bond, which generates an S(5) ring motif. Centrosymmetrically related molecules are linked via two pairs of intermolecular C—H⋯O interactions, forming R
2(16) ring motifs. In the crystal packing, the molecules are linked into two-dimensional networks parallel to the ab plane via C—H⋯O interactions.
In the title molecule, C34H53BrO4, all the cyclohexane rings adopt chair conformations, while the cyclopentane ring adopts an envelope conformation. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link the molecules into corrugated sheets parallel to the ab plane.
In each of the two independent indene-4-spiropentane molecules in the asymmetric unit of the title 2:1 adduct, C19H18N6·0.5C5H4OS, the cyclohexene ring adopts a half-chair conformation and the cyclopentene and cyclopentane rings adopt envelope conformations. The mean plane through the cyclohexene/cyclopentene fused system is aligned at a dihedral angle of 77.9 (1)° with respect to the mean plane through the cyclopentane ring in one molecule and 87.0 (1)° in the other. In the crystal, adjacent indene-4-spiropentane molecules are linked by N—H⋯N hydrogen bonds into a three-dimensional network. The spaces within the network are occupied by the thiophene-2-carbaldehyde molecules. The thiophene-2-carbaldehyde unit is disordered over two positions of equal occupancy. The crystal studied was found to be a non-morohedral twin with two minor twin components of 18.4 and 9.7%.
The title molecule, C21H28O5, is composed of three six-membered rings (A/B/C) and a five-membered ring (D). Ring A adopts a 1α-sofa conformation, while rings B and C adopt chair conformations. Cyclopentane ring D adopts a 14α-envelope conformation. In the crystal, O—H⋯O hydrogen bonds lead to the formation of ribbons running along the a axis. The structure is further consolidated by C—H⋯O interactions, which link the molecules head-to-tail into ribbons along the a axis.
The title compound, C8H14O4, is an isolation product of the aerial parts of Senecio desfontanei. The acetic acid group is oriented at a dihedral angle of 48.03 (9)° with respect to the basal plane of the cyclohexane-1,4-diol chair. An intramolecular O—H⋯O hydrogen bond generates an S(6) ring with an envelope conformation. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, resulting in R
3(20) ring motifs and C(2) O—H⋯O—H⋯O—H⋯ chains. Overall, a three-dimensional polymeric network arises. A C—H⋯O contact is also present.
In the title compound, C20H22O5, an S(6) ring motif is formed by an intramolecular C—H⋯O hydrogen bond, which contributes to the stabilization of the molecule. In the xanthene system, the cyclohexane ring adopts a chair conformation, the cyclohexene ring adopts a half-boat conformation and the tetrahydropyran ring adopts a half-chair conformation. The mean plane of the four essentially planar atoms of the tetrahydropyran ring [r.m.s deviation = 0.092 (1) Å] forms a dihedral angle of 64.13 (6)° with the mean plane of the methoxyphenyl group. In the crystal, intermolecular O—H⋯O and weak C—H⋯O hydrogen bonds link molecules into chains along the a axis, which are further stabilized by C—H⋯π interactions.
In the title compound, C20H22O5, the tetrahydropyran, cyclohexene and cyclohexane rings of the xanthene ring system adopt half-chair, half-boat and chair conformations, respectively. The mean plane of the four roughly planar atoms of the tetrahydropyran ring (r.m.s. deviation = 0.111 Å) forms a dihedral angle of 82.91 (4)° with the methoxybenzene group. In the crystal, molecules are linked via O—H⋯O and C—H⋯O hydrogen bonds into sheets lying parallel to the ac plane. The crystal is further consolidated by weak C—H⋯π interactions.
In the title compound, C19H19ClO4, the central fused ring and the attached cyclohexene ring adopt envelope conformations, while the cyclohexane ring adopts a chair conformation. The crystal packing is stabilized by O—H⋯O hydrogen bonds, which link the molecules into a chain along the b axis. Weak C—H⋯O bonds also occur.
In the title compound, C27H28N2O3, each of the pyrrolidine rings adopts a twisted conformation, as does the cyclopentane ring. The indane ring has an r.m.s deviation of 0.0693 Å. The dihedral angle between the mean plane of the pyrrolizine ring and indane system is 82.58 (1)°. The piperidine ring has the methyl substituent in an equatorial position and adopts a twisted chair conformation. The molecular structure is stabilized by a weak intramolecular O—H⋯N interaction.
The asymmetric unit of the title compound, C23H22N2O2, contains two independent molecules, A and B. The cyclohexane ring of molecule B is disordered, with occupancies for the major and minor conformers of 0.570 (9) and 0.430 (9), respectively. The cyclohexane ring adopts a boat conformation in molecule A and in the major conformer of molecule B, and a chair conformation in the minor conformer of molecule B. In both independent molecules, one of the dihydropyran rings adopts a boat conformation while the other is in a half-chair conformation. The dihedral angle between the pyrazole and phenyl rings is 16.0 (1)° in molecule A and 12.9 (1)° in molecule B. The crystal packing is stabilized by C—H⋯O and C—H⋯N intermolecular hydrogen bonds.
The title compound, C21H24N2O2, is a phenyl hydrazine derivative of the well known anthelminthic agent α-santonin, which is composed of three fused rings (benzodieneone, cyclohexane and γ-lactone). The cyclohexadienone ring adopts a boat conformation, the cyclohexane ring is in a chair conformation and the trans-fused γ-lactone ring adopts a C-envelope conformation. In the crystal, molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds, forming chains along the a axis.
In the title compound, C30H22BrNO2, the cyclopentane ring of the dihydroacenaphthylene group and the pyrrolidine ring are both in envelope conformations with the spiro C atom and N atom, respectively, as the flap atom. The cyclopentane ring of the indane group adopts a half-chair conformation. A weak intramolecular C—H⋯O hydrogen bond forms an S(8) ring motif. The naphthalene ring system of the dihydroacenaphthylene group forms dihedral angles of 41.76 (6) and 42.17 (6)° with the benzene ring of the bromophenyl group and the benzene ring of the indane group, respectively. The dihedral angle between the two benzene rings is 83.92 (7)°. In the crystal, molecules are linked by weak C—H⋯O and C—H⋯N hydrogen bonds into a two-dimensional network parallel to the ac plane. Weak C—H⋯π interactions are also observed.
The title compound, C19H29O4, was synthesized from 9α-hydroxyparthenolide (9α-hydroxy-4,8-dimethyl-12-methylen-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one), which was isolated from the chloroform extract of the aerial parts of Anvillea radiata. The molecule is built up from two fused five- and ten-membered rings with the pyrrolidin-1-ylmethyl group as a substituent. The five-membered lactone ring has an envelope conformation, whereas the ten-membered and pyrrolidine rings display approximate chair–chair and twisted conformations, respectively. The dihedral angle between the ten-membered ring and the lactone ring is 18.01 (19)°. An intramolecular O—H⋯N hydrogen bond occurs. The crystal structure is stabilized by weak intermolecular C—H⋯O hydrogen-bonding interactions.
In the title compound, C22H27BrO3, the cyclohexane ring adopts a chair conformation. The dihedral angle between the benzene rings is 41.9 (4)°. In the crystal, molecules are linked by O—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. In addition, π–π stacking interactions [centroid–centroid distance = 3.953 (6) Å] between the benzene rings of the methoxybenzene groups occur.
The asymmetric unit of the title compound, C29H24FNO5·0.5CH3OH, contains two independent molecules and a one methanol solvent molecule. The methanol molecule is O—H⋯O hydrogen bonded to one of the independent molecules. The pyrrolidine rings in both molecules adopt half-chair conformations, while the cyclopentane rings within the indane groups are in flattened envelope conformations, with the spiro C atoms forming the flaps. The benzene rings of the indane ring systems form a dihedral angle of 35.06 (7)° in one independent molecule and 31.16 (8)° in the other. The fluoro-substituted benzene ring forms dihedral angles of 65.35 (6) and 85.87 (7)° with the indane group benzene rings in one molecule, and 72.78 (8) and 77.27 (8)° in the other. In each molecule, a weak intramolecular C—H⋯O hydrogen bond forms an S(6) ring motif. In the crystal, weak C—H⋯O, C—H⋯N and C—H⋯F hydrogen bonds link the molecules into a three-dimensional network.
In the title molecule, C21H20N2O4, the dihedral angle between the phenol ring and the isoindole-1,3-dione mean plane is 69.79 (6)°. The cyclohexane ring adopts a chair conformation. Weak intermolecular O—H⋯O and O—H⋯N interactions feature as part of the crystal packing.
In the title compound, C15H25NO2, all three six-membered rings adopt chair conformations. The cyclohexane and piperidine rings within the perhydroisoquinoline are trans–trans fused. The N atom has a trigonal–pyramidal geometry (the sum of the bond angles is 328.0°). The methyl substituent occupies the sterically preferrable equatorial position. In the crystal, molecules form infinite  chains via O—H⋯N hydrogen bonds.