In the title compound, C14H17N3S, the plane of the phenyl ring makes a dihedral angle of 74.90 (4)° with that of the triazathione ring (r.m.s. deviation = 0.001 Å), while the seven-membered ring adopts a twist-chair conformation. No specific intermolecular interactions are discerned in the crystal packing.
The title compound was synthesized by treating (1S,3R,8S,9R,10S)-2,2-dichloro-3,7,7,10-tetramethyl-9,10-epoxytricyclo[6.4.0.01,3]dodecane with a concentrated solution of hydrobromic acid. It is built up from three fused rings: a cycloheptane ring, a cyclohexyl ring bearing alkene and hydroxy substituents, and a cyclopropane ring bearing two chlorine atoms.
The title compound, C16H24Cl2O, was synthesized by treating (1S,3R,8S,9R,10S)-2,2-dichloro-3,7,7,10-tetramethyl-9,10-epoxytricyclo[6.4.0.01,3]dodecane with a concentrated solution of hydrobromic acid. It is built up from three fused rings: a cycloheptane ring, a cyclohexyl ring bearing alkene and hydroxy substituents, and a cyclopropane ring bearing two chlorine atoms. The asymmetric unit contains two molecules linked by an O—H⋯O hydrogen bond. In the crystal, further O—H⋯O hydrogen bonds build up an R
4(8) cyclic tetramer. One of the molecules presents disorder that affects the seven-membered ring. In both molecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations intermediate between boat and twist-boat for the non-disordered molecule and either a chair or boat and twist-boat for the disordered molecule owing to the disorder. The absolute configuration for both molecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.
crystal structure; absolute configuration; sesquiterpenes; asymmetric synthesis; natural products; crystal structure
In the title compound, C13H15N3S, the 4,5-dihydro-3H-1,2,4-triazole ring is nearly planar [maximum deviation = 0.020 (1) Å], while the cyclohexane ring adopts a chair conformation. The dihedral angle between the 4,5-dihydro-3H-1,2,4-triazole ring and the phenyl ring is 74.68 (7)°. No specific intermolecular interactions are discerned in the crystal packing.
In the title compound, C12H13N3S, the 4,5-dihydro-3H-1,2,4-triazole system is nearly planar [maximum deviation = 0.014 (2) Å], while the cyclopentane ring adopts a half-chair conformation. The dihedral angle between the mean plane of the 4,5-dihydro-3H-1,2,4-triazole-3-thione ring and the phenyl ring is 85.49 (14)°, with the S atom 0.046 (1) Å out of the former plane. The crystal structure is stabilized only by van der Waals interactions. The investigated crystal was found to be a non-merohedral two-component twin by a 180° rotation about c*, with a refined value of the minor twin fraction of 0.12203 (18).
In the title trispiro compound, both the methyl-substituted pyrrolidine and dioxalane rings adopt a twist conformation. The cyclopentanone ring of the acenapthylen-1-one system adopts flattened envelope conformation, and the cyclohexanone attached to the dioxalane ring adopts boat conformation. In the crystal, centrosymmetrically related molecules are linked into dimers forming rings of (10) graph-set motif, which are further connected into chains parallel to the b axis by C—H⋯O contacts forming rings of (8) graph-set motif.
In the title compound, C36H31NO4, two spiro links connect the methyl-substituted pyrrolidine ring to the acenaphthylene and cyclohexanone rings. The cyclohexanone ring is further connected to the dioxalane ring by a third spiro junction. The five-membered ring of the acenaphthylen-1-one ring system adopts a flattened envelope conformation with the ketonic C atom as flap, whereas the dioxalane and pyrrolidine rings each have a twist conformation. The cyclohexanone ring assumes a boat conformation. Three intramolecular C—H⋯O hydrogen bonds involving both ketonic O atoms as acceptors are present. In the crystal, C—H⋯O hydrogen bonds connect centrosymmetrically related molecule into chains parallel to the b axis, forming rings of R
2(8) graph-set motifs.
crystal structure; trispiropyrrolidines; acenaphthylene; spirocyclohexanones; dioxalane
In the title compound, C33H28N2O4, the central pyrrolidine ring adopts a half-chair conformation. Both the indolinone and indanone groups are twisted, with their five-membered rings adopting a half-chair and an envelope conformation, respectively. The two benzene rings and the mean plane of the indolinone and indanone groups make dihedral angles of 71.98 (10), 84.32 (10), 86.26 (9) and 78.50 (9)°, respectively, with the central pyrrolidine ring. Intramolecular C—H⋯O hydrogen bonds stabilize the molecular conformation. In the crystal, pairs of intermolecular N—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers. The dimers are interconnected into ribbons propagating along  via weak intermolecular C—H⋯O hydrogen bonds. Weak intermolecular C—H⋯π and π–π [centroid–centroid distance = 3.6509 (11) Å] interactions are also observed.
In an endeavor directed towards the construction of the oxabicyclic[3.2.1]octane segment present in the bioactive natural products of cortistatins and icetexanes genre, the title compound, C13H19BrO3, was synthesized from (4aR,9aS)-1,3,4,4a,5,6,9,9a-octahydrospiro[benzoannulene-2,2′-[1,3]dioxolane]-4a-ol via a transannular bromo-etherification protocol. The six-membered ring adopts a twist-boat conformation, while the fused cycloheptane ring adopts a chair conformation. The crystal packing is effected through two distinct intermolecular C—H⋯O hydrogen-bond patterns and molecules are arranged to define an interesting motif along the b axis.
In the title spiro-phosphazene derivative, C33H46N9OP3, the phosphazene and six-membered N/O rings are in flattened chair and twisted-boat conformations, respectively. The naphthalene ring system and the pyridine ring are oriented at a dihedral angle of 41.82 (4)°. In the crystal, weak C—H⋯O hydrogen bonds link the molecules related by translation along the a axis into chains. C—H⋯π interactions aggregate these chains into layers parallel to the ab plane.
The conformation of the piperidine ring is modified by the hybridization state of the C atom in the α-position to the piperidinic N atom.
The crystal structures of the two title piperidine derivatives show different conformations for the six-membered heterocycle. The N-substituted 4-piperidinone 1-[(1R)-2-hydroxy-1-phenylethyl]piperidin-4-one, C13H17NO2, (I), has a chair conformation, while the piperidine substituted in position 2 with a thiocarbonyl group, 8-[(1S)-1-phenylethyl]-1,4-dioxa-8-azaspiro[4.5]decane-7-thione, C15H19NO2S, (II), features a half-chair conformation. Comparison of the two structures, and data retrieved from the literature, suggests that the conformational flexibility is mainly related to the hybridization state of the C atom α to the piperidinic N atom: a Csp
3 atom favours the chair conformer, while a Csp
2 atom distorts the ring towards a half-chair conformer. In the crystal structure of (I), weak C—H⋯O hydrogen bonds link the molecules into supramolecular chains propagating along the b-axis direction. In the crystal of (II), the molecules are linked by weak C—H⋯S contacts into supramolecular chains propagating along the b-axis direction.
crystal structure; piperidine; piperidone; thione; ring conformation
The asymmetric unit of the title compound, C34H31N3O2, consists of two independent molecules which differ slightly in the orientations of the phenyl rings with respect to the pyrrolidine ring. In both molecules, the piperidin-4-one ring adopts a chair conformation, whereas the pyrrolidine ring adopts an envelope conformation in one of the molecules and a twisted conformation in the other. An intramolecular C—H⋯O hydrogen bond is observed. The crystal packing is stabilized by intermolecular N—H⋯O hydrogen bonds and C—H⋯π interactions.
In the title compound, C22H24N2O6, the indole ring has a twist conformation and the tetrahydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the ‘butterfly’ angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetrahydrofuran ring has an envelope conformation on the C atom in the fused tetrahydro-2H-pyran-2-one ring adjacent to the O atom of the tetrahydrofuran ring. The ‘butterfly’ angle between the mean planes of these two five-membered rings is 69.14 (10)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming chains along the a axis.
In the title compound, C23H23NO8, the dihedral angle between the five- and six-membered rings of the indene-dione moiety is 3.09 (13)°. The mean plane of the five-membered ring (which has a flat envelope conformation with the spiro C atom as the flap) is inclined to the mean plane of the central five-membered ring of the pyrrolizine unit by 76.48 (12)°. This central ring has a twist conformation on the N—C(spiro) bond. The outer ring of the pyrrolizine unit has an envelope conformation with the N atom as the flap. The mean planes of these two fused rings are inclined to one another by 65.28 (15)°. The pyran ring has a screw-boat conformation and its mean plane makes a dihedral angle of 29.50 (11)° with the mean plane of the central five-membered ring of the pyrrolizine unit. In the crystal, molecules are linked via C—H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane.
In the title compound, C36H29Cl2NO4, two spiro links connect the methyl-substituted pyrrolidine ring to the acenaphthylene and cyclohexanone rings. The cyclohexanone ring is further connected to the dioxalane ring by a third spiro junction. The five-membered ring of the acenaphthylen-1-one ring system adopts a flattened envelope conformation, with the ketonic C atom as the flap, whereas the dioxalane and pyrrolidine rings each have a twist conformation. The cyclohexenone ring assumes a boat conformation. An intramolecular C—H⋯O hydrogen-bond interaction is present. In the crystal, molecules are linked by non-classical C—H⋯O hydrogen bonds, forming chains extending parallel to the a axis.
crystal structure; spiro pyrrolidines; acenaphthylene; dioxalane; hydrogen bonding
The title compound, C23H23NO, is the product of a tandem transformation of the double Mannich base bis(1-oxo-1,2,3,4-tertrahydro-2-naphthoylmethyl)amine hydrochloride in HBr solution upon heating. The tetrahydropyridine ring has a non-symmetrical half-chair conformation, whereas the cyclohexadiene and cyclohexene rings adopt non-symmetrical half-boat conformations. The dihedral angle between the planes of the terminal benzene rings is 62.85 (6)°. The N atom has a trigonal–pyramidal geometry [sum of the bond angles = 332.4 (3)°]. In the crystal, molecules form  chains via weak non-classical C—H⋯N hydrogen bonds. The chains are stacked along the b axis.
In the title compound, the dioxolane and cyclohexane rings adopt twist and chair conformations, respectively. In the crystal, intra- and intermolecular O—H⋯O hydrogen bonds are observed.
In the title compound, C9H16O4, the five-membered dioxolane ring adopts a twist conformation; two adjacent C atoms deviate alternately from the mean plane of other atoms by −0.297 (4) and 0.288 (4) Å. The spiro-fused cyclohexane ring shows a chair form. The hydroxy group substituted in an axial position makes an intramolecular O—H⋯O hydrogen bond with one of the O atoms in the cyclic ether, forming an S(6) ring motif. In the crystal, the O—H⋯O hydrogen bond involving the equatorial hydroxy group connects the molecules into a zigzag chain with a C(5) motif running along the c axis.
crystal structure; hydrogen bonds; paclitaxel; cyclohexane; hydroxy groups
The thiazolidine ring and the pyrrolidine ring in the title compound, C25H26N2O2S, both adopt an envelope conformation. The seven-membered ring has a twist-chair conformation. The crystal packing is stabilized by intermolecular N—H⋯O hydrogen bonds.
In the title compound, C27H19ClFN3O3, the pyrazole ring has a twist conformation and the six-membered ring to which it is fused has a screw-boat conformation. The mean plane of the pyrazole ring is inclined to the 2-methylindoline ring by 85.03 (9) and by 28.17 (8)° to the mean plane of the isoquinoline ring system. In the crystal, molecules are linked by pairs of C—H⋯F hydrogen bonds, forming inversion dimers. These dimers are linked via C—H⋯O hydrogen bonds, forming a two-dimensional network lying parallel to (10-1).
In the title compound, C31H25N5O3·C2H6OS, the three indole/indoline units are all essentially planar with maximum deviations of 0.0172 (3), 0.053 (2) and 0.07 (2) Å. The pyrrolidine ring adopts an envelope conformation with the C atoms bearing the 1-ethyl-2-oxoindole substituent (in which the five-membered ring adopts a twisted conformation) as the flap. The dimethyl sulfoxide solvent molecule is disordered over two positions, with an occupancy factor ratio of 0.871 (4):0.129 (4). The solvent components are linked to the heterocyclic molecule via C—H⋯O and C—H⋯S hydrogen bonds. In the crystal, the solvent components are linked to the heterocyclic molecule via C—H⋯O and C—H⋯S interactions, forming R
2(10) ring motifs. The molecules are further connected into a chain along the a-axis direction via N—H⋯O hydrogen bonds.
The asymmetric unit of the title compound, C43H34Cl4N4O3, contains two crystallographically independent molecules. In both molecules, the pyrrolidine ring adopts a twist conformation, the oxindole units are slightly distorted from planarity and the isoxazoline ring adopts an envelope conformation. The crystal structure is stabilized by N—H⋯O hydrogen-bonding interactions giving one-dimensional chain structures.
The title compound, C19H16F4O4, was prepared by the condensation reaction of 2,6-difluorobenzaldehyde and pentaerythritol. The whole molecule is generated by twofold rotational symmetry. The two six-membered O-heterocycles adopt chair conformations through a shared spiro-carbon atom that is located on the crystallographic twofold rotation axis. In this conformation, the two aromatic rings are located at the equatorial positions of the O-heterocycles. The conformation of this doubly substituted tetraoxaspiro system is chiral. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to (100). These layers are linked by C—H⋯F hydrogen bonds into a three-dimensional structure.
crystal structure; oxo-spirocyclic; helical hydrogen-bonded chains; axial chirality
In the title compound, C22H18BrN5O4, the central six-membered ring, derived from 1,4-dihydropyridine, adopts a distorted boat conformation with a puckering amplitude of 0.197 (3) Å, the imidazole ring adopts a twisted conformation with a puckering amplitude of 0.113 (3) Å, and the oxindole moiety is planar with an r.m.s. deviation of 0.0125 Å. Two intramolecular N—H⋯O hydrogen bonds are formed, each closing an S(6) loop. In the crystal, strong N—H⋯O hydrogen bonds lead to the formation of zigzag chains along the c axis. These are consolidated in the three-dimensional crystal packing by weak N—H⋯O hydrogen bonding, as well as by C—H⋯O, C—H⋯Br and C—H⋯π interactions. A small region of electron density well removed from the main molecule was removed with the SQUEEZE procedure in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155] following unsuccessful attempts to model it as a plausible solvent molecule. The unit-cell characteristics do not take into account this feature of the structure.
In the title compound, C25H23FN2O4S, the fused piperidine ring of the octahydroindolizine ring system adopts a chair conformation and the five-membered ring has a twisted conformation on the N—C(spiro) bond. The mean planes of the benzothiophene and indoline ring systems are inclined to the mean plane of the pyrrolidine ring by 83.1 (1) and 84.9 (1)°, respectively, and to each other by 29.37 (17)°. In the crystal, molecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R
2(8) ring motif. The dimers are linked via C—H⋯O hydrogen bonds, forming slabs lying parallel to (100). The packing between the slabs features a short [2.734 (2) Å] F⋯F contact.
crystal structure; dispiro; benzothiophene; indolizine; indoline; F⋯F interactions; hydrogen bonds
The absolute structure for the title compound, which has five chiral centres has been determined in this analysis. The supramolecular architecture comprises parallel zigzag chains formed through N—H⋯N and C—H⋯O hydrogen bonds, as well as intramolecular C—H⋯O, C—H⋯N and C—H⋯π interactions.
In the title compound, C24H32BrN3O2, the six-membered cyclohexane ring adopts a chair conformation and the isoxasolidine ring adopts a twisted conformation. The molecule has five chiral centres and the absolute configuration has been determined in this analysis. The molecular structure is stabilized by weak intramolecular C—H⋯O and C—H⋯N contacts. In the crystal, molecules are linked by N—H⋯N and C—H⋯O hydrogen bonds, forming undulating sheets parallel to the bc plane.
crystal structure; isoxazolidines; 1,3-dipolar cycloaddition; chiral nitrone; hydrogen bonding
In the title compound, C15H26N2O2S, the cyclohexane and morpholine rings adopt chair conformations, while the thiazole ring has a twist conformation. An intramolecular C—H⋯S hydrogen-bond interaction forms a five-membered ring. The crystal packing involves C—H⋯O=C intermolecular interactions where carbonyl O atoms act as double acceptors to two symmetrically related H atoms.
In the title compound, C18H21NO4, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation. The dioxolane ring and ethylacetate substituent point to opposite sides of the carbazole plane. The ethylacetate substituent adopts an essentially fully extended conformation, and its mean plane forms a dihedral angle of 83.8 (1)° with respect to the carbazole mean plane. The molecules are arranged into stacks in which the carbazole planes form a dihedral angle of 4.4 (1)° and have an approximate interplanar separation of 3.6 Å.