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1.
G. Vasuki V. Parthasarathi K. Ramamurthi D. P. Jindal S. Dubey 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1062-1063
The title compound, C25H31NO2·H2O, has the outer two six‐membered rings in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐membered ring adopts a 13,14‐half‐chair conformation. The pyridylmethylene moiety has an E configuration with respect to the carbonyl group at position 17. The structure is stabilized by intermolecular O—H?N and O—H?O hydrogen bonds. 相似文献
2.
G. Vasuki S. Thamotharan V. Parthasarathi K. Ramamurthi S. Dubey D. P. Jindal 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(10):o598-o599
The title compound, C32H45N2O+·Br?·0.5H2O, has the outer two six‐membered rings in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐membered ring of the steroid nucleus adopts a slightly deformed 14α‐envelope conformation. The pyridylmethylene moiety has an E configuration with respect to the hydroxyl group at position 17. The structure is stabilized by a network of O—H?Br‐type intermolecular hydrogen bonds. 相似文献
3.
R. Hema V. Parthasarathi S. Thamotharan S. Dubey D. P. Jindal 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o421-o422
In the title compound, C31H40N2O·H2O, the outer two six‐membered rings are in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐membered ring adopts a 13β‐envelope conformation and the cyanobenzylidene moiety has an E configuration with respect to the hydroxyl group at position 17. The steroid nuclei are linked by intermolecular O—H?O and O—H?N hydrogen bonds to form a molecular network. The molecular packing has an interesting feature, with the steroids aligned parallel to the b axis, forming a closed loop through hydrogen bonds linked via water molecules. 相似文献
4.
Andrzej Gzella 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):505-507
The X‐ray crystal structure analyses of 3β‐hydroxy‐11‐oxo‐18α‐olean‐12‐en‐28‐oic acid methyl ester ethanol solvate, C31H48O4·C2H6O, (I), and 3,11‐dioxo‐18α‐olean‐12‐en‐28‐oic acid methyl ester, C31H46O4, (II), are described. These two compounds differ only in the structure of ring A. In (I), ring A has a chair conformation, while in (II), it has a twisted boat conformation. In both compounds, ring C has a slightly distorted sofa conformation, rings B, D and E are in chair conformations, and rings D and E are trans‐fused. The asymmetric unit of (I) contains one molecule of ethanol linked by hydrogen bonds with two different molecules of (I). 相似文献
5.
16‐[3‐Methoxy‐4‐(2‐piperidin‐1‐ylethoxy)benzylidene]‐17‐oxoandrost‐5‐en‐3β‐yl acetate monohydrate
S. Thamotharan V. Parthasarathi Ranju Gupta Sheetal Guleria D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o727-o729
The title compound, C36H49NO5·H2O, has the outer two six‐membered rings of the steroid nucleus in chair conformations. The central ring B of the steroid nucleus is in an 8β,9α‐half‐chair conformation, while ring D of the steroid adopts a slightly distorted 13β,14α‐half‐chair conformation. The piperidine ring is in a chair conformation. The methoxybenzylidene moiety has an E configuration with respect to the carbonyl group at position 17. Intermolecular O—H?O and O—H?N hydrogen bonds link the steroid and water molecules into chains which run parallel to the b axis. 相似文献
6.
Zbigniew Karczmarzyk Wiesaw Malinka 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(8):o477-o480
In the crystal structures of the title compounds, C20H23N3OS, (II), and C20H21N3OS, (III), significant differences occur in the conformation of, respectively, the phenylpiperidine and phenyltetrahydropyridine substituents at the 2‐position of the isothiazolopyridine system. The piperidine ring adopts a chair conformation, while the tetrahydropyridine ring assumes a half‐chair form. The phenylpiperidine and phenyltetrahydropyridine fragments exhibit different conformations resulting from the steric and conjugation effects in the phenyl ring, respectively. Theoretical calculations show that both conformations are energetically stable and correspond to a minimum of energy for the analyzed systems. The molecular packing in (II) is influenced by π–π interactions of the isothiazolopyridine systems, with a shortest centroid‐to‐centroid separation of 3.5843 (11) Å between pyridine rings. In the crystal structure of (III), the molecules are linked by C—H...O hydrogen bonds and C—H...π interactions. 相似文献
7.
Carlos A. Zelaya Edwin D. Stevens Michael K. Dowd 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(10):o517-o520
6,6′‐Dimethoxygossypolone (systematic name: 7,7′‐dihydroxy‐5,5′‐diisopropyl‐6,6′‐dimethoxy‐3,3′‐dimethyl‐1,1′,4,4′‐tetraoxo‐2,2′‐binaphthalene‐8,8′‐dicarbaldehyde), C32H30O10, is a dimeric molecule formed by oxidation of 6,6′‐dimethoxygossypol. When crystallized from acetone, 6,6′‐dimethoxygossypolone has monoclinic (P21/c) symmetry, and there are two molecules within the asymmetric unit. Of the four independent quinoid rings, three display flattened boat conformations and one displays a flattened chair/half‐chair conformation. The angles between the planes of the two bridged naphthoquinone structures are fairly acute, with values of about 68 and 69°. The structure has several intramolecular O—H...O and C—H...O hydrogen bonds and several weak intermolecular C—H...O hydrogen bonds, but no intermolecular O—H...O hydrogen bonds. 相似文献
8.
Daniel Fernndez Daniel Vega Javier A. Ellena 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o187-o189
The title compound, C22H28O5, is a commercial therapeutic agent of the steroid class. Both independent molecules in the asymmetric unit have six‐membered A rings that are planar, while the B and C rings adopt normal chair conformations. The five‐membered D ring is in a 13β,14α‐half‐chair conformation, and the B/C and C/D ring junctions are in trans positions. Cohesion in the crystal is provided by O—H⃛O hydrogen bonds, which generate chains of molecules that are organized in a plane that lies along the crystallographic b axis. 相似文献
9.
Waseeq Ahmad Siddiqui Saeed Ahmad Muhammad Ilyas Tariq Hamid Latif Siddiqui Masood Parvez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(1):o4-o6
The structures of N‐(2‐chlorophenyl)‐4‐hydroxy‐2‐methyl‐2H‐1,2‐benzothiazine‐3‐carboxamide 1,1‐dioxide and N‐(4‐chlorophenyl)‐4‐hydroxy‐2‐methyl‐2H‐1,2‐benzothiazine‐3‐carboxamide 1,1‐dioxide, both C16H13ClN2O4S, are stabilized by extensive intramolecular hydrogen bonds. The 4‐chloro derivative forms dimeric pairs of molecules lying about inversion centres as a result of intermolecular N—H...O hydrogen bonds, forming 14‐membered rings representing an R22(14) motif; the 2‐chloro derivative is devoid of any such intermolecular hydrogen bonds. The heterocyclic thiazine rings in both structures adopt half‐chair conformations. 相似文献
10.
L. C. R. Andrade J. A. Paixo M. J. M. de Almeida E. J. Tavares da Silva M. L. S e Melo F. M. Fernandes Roleira 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o82-o83
The title compound, alternatively called 24‐nor‐5β‐chol‐22‐ene‐3β,7α,12α‐triyl triformate, C26H38O6, has a cis junction between two of the six‐membered rings. All three of the six‐membered rings have chair conformations that are slightly flattened and the five‐membered ring has a 13β,14α‐half‐chair conformation. The 3β, 7α and 12α ring substituents are axial and the 17β group is equatorial. The 3β‐formyloxy group is involved in one weak intermolecular C—H⋯O bond, which links the molecules into dimers in a head‐to‐head fashion. 相似文献
11.
Nurten Ezer Anthony Linden F. Pnar ahin hsan al 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o253-o255
The ent‐kaurene diterpene in the title compound, 7‐epicandicandiol ethanol solvate, C20H32O2·C2H6O, was isolated from the aerial parts of Sideritis ozturkii Aytaç & Aksoy. The molecule has the usual conformation and stereochemistry found in related ent‐kaurene derivatives. The methyl‐substituted ring junction has a trans arrangement and the other junction is cis. The six‐membered rings have chair or slightly distorted chair conformations and the five‐membered ring has an envelope conformation. Intermolecular hydrogen bonds link the 7‐epicandicandiol and ethanol molecules into two‐dimensional networks, part of which comprise co‐operative O—H⋯O—H⋯O—H⋯ chains. 相似文献
12.
R. Hema V. Parthasarathi S. Thamotharan S. Dubey D. P. Jindal 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o213-o215
In the title compound, 4‐(3β‐hydroxy‐17‐oxoandrost‐5‐en‐16‐ylidenemethyl)benzonitrile, C27H31NO2, rings A and C of the steroid nucleus are in chair conformations. The central six‐membered ring B is in an 8β,9α‐half‐chair conformation, while the five‐membered ring D adopts a 13β,14α‐half‐chair conformation. The cyanobenzylidene moiety has an E configuration with respect to the carbonyl group at position C17. The dihedral angle between the planes of the steroid nucleus and the cyanobenzylidene moiety is 22.61 (15)°. Intermolecular O—H⃛N hydrogen bonds formed between the hydroxyl group of the steroid and the N atom of the cyanobenzylidene moiety of symmetry‐related molecules link the steroid molecules into chains which run parallel to the b axis. 相似文献
13.
Kinkini Bhattacharyya Tanusree Kar Rex A. Palmer Brian S. Potter Akira Inada 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):979-980
In the title compound, C30H50O3, the three six‐membered rings adopt chair, twist and twist‐boat conformations. The five‐membered ring is in a slightly distorted envelope conformation. The substituent on the five‐membered ring is in an extended conformation, with its two hydroxyl O atoms forming an intramolecular hydrogen bond. One of these O atoms also forms an intermolecular hydrogen bond with the oxygen of the carbonyl group in a neighbouring molecule. 相似文献
14.
S. Thamotharan V. Parthasarathi Ranju Gupta D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o161-o162
In the title compound, C23H31N3O3, the outer cyclohexane rings have chair conformations, while the central cyclohexene ring adopts a half‐chair conformation. In the solid state, intra‐ and intermolecular C—H⋯N interactions are observed. 相似文献
15.
Michael Benn Masood Parvez Oliver Edward Edwards 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o283-o285
The structure of the title compound, C23H35NO4, contains a unique pentacyclic ring system wherein one cyclohexyl ring adopts a chair conformation, two cyclohexyl rings are in boat conformations, and a six‐membered heterocyclic ring and a cyclopentyl ring are in envelope conformations. The structures of the lycoctamones, α,β‐unsaturated aldehydes produced by acid‐catalyzed degradation of lactams of lycoctonine‐type alkaloids, previously deduced from the results of extensive chemical investigations have been proven to be correct by the determination of the crystal structure of this compound. 相似文献
16.
Andrzej Gzella 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):983-985
The structures of methyl 3β‐acetoxy‐12‐oxo‐18β‐olean‐28‐oate [C33H52O5, (I)] and methyl 3β‐acetoxy‐12,19‐dioxoolean‐9(11),13(18)‐dien‐28‐oate [C33H46O6, (II)] are described. In (I), all rings are in the chair conformation, rings D and E are cis and the other rings trans‐fused. In compound (II), only rings A and E are in the chair conformation, ring B has a distorted chair conformation, ring C a distorted half‐boat and ring D an insignificantly distorted half‐chair conformation. 相似文献
17.
Masood Parvez M. Saeed Arayne Rizwana Sabri Najma Sultana 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e398-e399
The absolute configuration was determined for the title compound, C38H70NO13+·Cl?·3.5H2O. The cation contains a 14‐membered macrocyclic lactone and two sugars, namely cladinose and desosamine. The six‐membered rings of the sugars adopt chair conformations. The structure is stabilized by strong hydrogen bonds, with O?O distances in the range 2.486 (9)–2.830 (5) Å; other distances are N?O = 2.860 (5), N?Cl = 3.134 (4) and O?Cl = 3.303 (4) Å. 相似文献
18.
Mahbod Morshedi Soraia Meghdadi Kurt J. Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):m87-m89
The quinquedentate ligand 2,2′‐[1,1′‐(4‐azaheptane‐1,7‐diyldinitrilo)diethylidyne]diphenol in the title compound, [Cu(C22H27N3O2)], furnishes an N3O2 donor set, which results in a distorted square‐pyramidal coordination; the two O and two imine N atoms lie in the basal plane, while the secondary amine N atom of the ligand occupies the axial position. The axial Cu—N bond is 0.33 Å longer than the average of the equatorial bonds, and the O atoms are trans. The symmetry of the molecule is lowered by the twist–boat and chair conformations adopted by the two CuNN chelate rings. The complex contains two intramolecular C—H⋯O interactions, and two molecules of the complex are linked into a dimer by means of moderate N—H⋯O hydrogen bonds. Spectroscopic evidence supports the presence of hydrogen bonds. 相似文献
19.
A. Abdul Ajees N. Palani K. K. Balasubramanian 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o433-o435
The six‐membered ring of the norbornene moiety in the title compound, C18H18N4O4, is in a slightly distorted boat conformation, and the two five‐membered rings within it adopt envelope conformations. The structure is stabilized by inter‐ and intramolecular N—H?O hydrogen bonds. 相似文献
20.
Levent
ztürk Muhammed Iklan Zeynel Kl Tuncer Hkelek 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o80-o83
The title compound, C26H55N11P4, consists of a bicyclic phosphazene ring with five bulky pyrrolidino and one propylamino group, together with a second propylamino group bridging the two P atoms. The asymmetric unit contains two molecules with very similar conformations. The bulky substituents are instrumental in determining the bicyclic P4N5 ring conformation. Each of the fused six‐membered N3P3 rings is in a sofa conformation. The P—N distances in the bridge are non‐equivalent and one of them is the longest P—N bond in the molecule. The hybridization of the bridging N atom is pyramidal. The single and double P—N bonds cannot easily be distinguished, since they retain their phosphazenic character in the phosphazene macro‐rings. 相似文献