14-Acetyl-20-ethyl-1,8-dihydroxy-16,18-dimethoxylycoctonine

2006 ◽  
Vol 62 (4) ◽  
pp. o1428-o1430 ◽  
Author(s):  
Manzoor Ahmad ◽  
Shamsher Ali ◽  
Farzana Shaheen ◽  
Shazia Anjum ◽  
M. Iqbal Choudhary
Keyword(s):  
Hydrogen Bonds ◽  
Chair Conformation ◽  
The Other ◽  
Piperidine Ring ◽  
Boat Conformation ◽  
Compound C ◽  
Twist Conformation ◽  
Cyclopentane Ring ◽  
Fused Ring ◽  
Twist Boat

The title compound (C25H39NO6), a polycyclic diterpenoid alkaloid, has been isolated from Delphinium roylei Munz. Two cis-fused ring junctions are observed between cyclohexane A and piperidine E rings and between cyclohexane B and cyclopentane C rings. Two trans-fused ring junctions involve cyclohexane A and cyclopentane B rings and also piperidine E and cyclopentane F rings. Cyclopentane ring F is in a twist conformation, while the other cyclopentane ring, C, forms an envelope conformation. Piperidine ring E is in a chair conformation, the two cyclohexane rings A and B adopt twist–boat conformations and cyclohexane ring D is in a screw-boat conformation. Of the five substituents, only one is α-oriented. The molecules are packed along the c axis in layers parallel to the ab plane and stabilized by weak inter- and intramolecular O—H...O and O—H...N hydrogen bonds.

scholarly journals 3β-Chloro-5α-cholestan-6-one

2012 ◽  
Vol 68 (4) ◽  
pp. o1211-o1212
Author(s):  
Samina Khan Yusufzai ◽  
Hasnah Osman ◽  
Aisyah Saad Abdul Rahim ◽  
Suhana Arshad ◽  
Ibrahim Abdul Razak
Keyword(s):  
Hydrogen Bonds ◽  
Chair Conformation ◽  
The Other ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Compound C ◽  
Dimensional Network ◽  
Cyclopentane Ring ◽  
Fused Ring ◽  
Independent Molecules

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).

scholarly journals (E)-3,3,6,6-Tetramethyl-9-(2-nitrostyryl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione

2012 ◽  
Vol 68 (6) ◽  
pp. o1947-o1947 ◽  
Author(s):  
Jae Kyun Lee ◽  
Sun-Joon Min ◽  
Yong Seo Cho ◽  
Ki Soo Lee ◽  
Joo Hwan Cha
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Chair Conformation ◽  
The Other ◽  
Boat Conformation ◽  
Pyran Ring ◽  
Compound C

In the title compound, C25H27NO5, each of the cyclohexenone rings adopts a half-chair conformation, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms. In the crystal, weak C—H...O hydrogen bonds link molecules into chains parallel to the c axis.

scholarly journals Crystal structure of 16-hydroxy-4,4,10,13,14-pentamethyl-17-(6-methylhept-5-en-2-yl)-4,5,6,9,10,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3(2H)-one

2015 ◽  
Vol 71 (7) ◽  
pp. o464-o465 ◽  
Author(s):  
Jun-Jun Ge ◽  
Pian Chen ◽  
Xiao-Xia Ye
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Chair Conformation ◽  
Membered Ring ◽  
Boat Conformation ◽  
Carbonyl Groups ◽  
Compound C ◽  
Cyclohexene Ring ◽  
Supramolecular Chains ◽  
Twist Boat

The title compound, C30H48O2, contains a fused four-ring triterpenoid system. In the molecule, the two cyclohexane rings adopt a chair conformation and a twist boat conformation, respectively, the central cyclohexene ring adopts a half-chair conformation whereas the five membered ring adopts an envelope conformation. In the crystal, O—H...O hydrogen bonds between the hydroxy and carbonyl groups of adjacent molecules link the molecules into supramolecular chains propagating along theb-axis direction.

scholarly journals Crystal structure of 2-chloro-1-(3-methyl-2,6-diphenylpiperidin-1-yl)ethanone

2015 ◽  
Vol 71 (2) ◽  
pp. o135-o136
Author(s):  
V. Shreevidhyaa Suressh ◽  
K. Prathebha ◽  
S. Abdul Basheer ◽  
S. Ponnuswamy ◽  
G. Usha
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Piperidine Ring ◽  
Boat Conformation ◽  
Π Interactions ◽  
Compound C ◽  
Phenyl Rings ◽  
Twist Boat

In the title compound, C20H22ClNO, the piperidine ring has a twist-boat conformation. There is an intramolecular C—H...π interaction involving the two phenyl rings which are inclined to one another by 84.91 (7)°. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming helical chains along [010]. The chains are linked by C—H...π interactions, forming sheets parallel to (100).

scholarly journals 2-[4-(Piperidin-1-yl)-5H-chromeno[2,3-d]pyrimidin-2-yl]phenol

2014 ◽  
Vol 70 (4) ◽  
pp. o447-o448 ◽  
Author(s):  
Naresh Sharma ◽  
Goutam Brahmachari ◽  
Suvankar Das ◽  
Rajni Kant ◽  
Vivek K. Gupta
Keyword(s):  
Benzene Ring ◽  
Chair Conformation ◽  
Pyrimidine Ring ◽  
Piperidine Ring ◽  
Maximum Deviation ◽  
Boat Conformation ◽  
Π Interactions ◽  
Compound C ◽  
Ring Centroid ◽  
Twist Boat

In the title compound, C22H21N3O2, the pyrimidine ring is essentially planar [maximum deviation = 0.018 (2) Å] and forms dihedral angles of 22.70 (8) and 0.97 (7)°, respectively, with the fused benzene ring and the hydroxy-substituted benzene ring. The piperidine ring has a chair conformation and the pyran ring has a flattened twist-boat conformation. The hydroxy group was refined as disordered over two sets of sites in a 0.702 (4):0.298 (4) ratio. The disorder corresponds to a rotation of approxomiately 180° about the C—C bond connecting the phenol group to the pyrimidine ring and hence, both the major and minor components of disorder form intramolecular O—H...N hydrogen bonds. In the crystal, pairs of weak C—H...π interactions form inversion dimers. In addition, π–π interactions are observed between the pyrimidine ring and the hydroxy-substituted benzene ring [centroid–centroid separation = 3.739 (2) Å].

scholarly journals 5-Chloro-5′′-(4-chlorobenzylidene)-4′-(4-chlorophenyl)-1′,1′′-dimethyldispiro[indoline-3,2′-pyrrolidine-3′,3′′-piperidine]-2,4′′-dione

2014 ◽  
Vol 70 (3) ◽  
pp. o379-o380 ◽  
Author(s):  
I. S. Ahmed Farag ◽  
Adel S. Girgis ◽  
A. A. Ramadan ◽  
A. M. Moustafa ◽  
Ahmed F. Mabied
Keyword(s):  
Hydrogen Bonds ◽  
Chair Conformation ◽  
The Other ◽  
Piperidine Ring ◽  
Dihedral Angles ◽  
Pyrrolidine Ring ◽  
Compound C ◽  
Benzene Rings ◽  
Ribbon Structure ◽  
Graph Set

The racemic title compound, C30H26Cl3N3O2, comprises two spiro links, the first connecting the piperidine and pyrrolidine rings and the other connecting the indole and pyrrolidine rings. The piperidine ring adopts a half-chair conformation, while the pyrrolidine ring has an envelope conformation with the unsubstituted C atom as the flap. The dihedral angles between the twop-Cl-substituted benzene rings and the indole ring are 33.13 (14) and 54.11 (14)°. In the crystal, molecules form inversion dimers through pairs of N—H...O hydrogen bonds [graph setR22(8)]. Aromatic C—H...O hydrogen bonds extend these dimers into a ribbon structure, enclosingR22(14) ring motifs, along thea-axis direction.

scholarly journals Crystal structure of (E)-4-(acetoxyimino)-N-allyl-3-isopropyl-2,6-diphenylpiperidine-1-carbothioamide

2015 ◽  
Vol 71 (8) ◽  
pp. o542-o543
Author(s):  
T. Mohandas ◽  
K. Gokula Krishnan ◽  
S. Balamurugan ◽  
William T. A. Harrison ◽  
V. Thanikachalam ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Piperidine Ring ◽  
Side Chain ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Compound C ◽  
Phenyl Rings ◽  
Twist Boat

The title compound, C26H31N3O2S, crystallizes with two molecules (AandB) in the asymmetric unit. In each case, the piperidine ring exists in a twist-boat conformation. The dihedral angle between the phenyl rings is 46.16 (12)° in moleculeAand 44.95 (12)° in moleculeB. In both molecules, the allyl side chain is disordered over two orientations in a 0.649 (9):0.351 (9) ratio for moleculeAand 0.826 (10):0.174 (10) ratio for moleculeB. In the crystal, neither molecule forms a hydrogen bond from its N—H group, presumably due to steric hindrance.A+AandB+Binversion dimers are formed, linked by pairs of weak C—H...O hydrogen bonds enclosingR22(22) ring motifs.

scholarly journals Crystal structure of methyl 4-(2-fluorophenyl)-6-methyl-2-sulfanylidene-1,2,3,4-tetrahydropyrimidine-5-carboxylate

2015 ◽  
Vol 71 (11) ◽  
pp. o838-o839
Author(s):  
M. S. Krishnamurthy ◽  
Noor Shahina Begum
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Pyrimidine Ring ◽  
The Other ◽  
Boat Conformation ◽  
Specific Interactions ◽  
Compound C ◽  
The Mean ◽  
Supramolecular Chains ◽  
Twist Boat

In the title compound, C13H13FN2O2S, the pyrimidine ring adopts a twist-boat conformation with the MeCNand methine-Catoms displaced by 0.0938 (6) and 0.2739 (3) Å, respectively, from the mean plane through the other four atoms of the ring. The 2-fluorobenzene ring is positioned axially and forms a dihedral angle of 89.13 (4)° with the mean plane through the pyrimidine ring. The crystal structure features N—H...O, N—H...S and C—H...O hydrogen bonds that link molecules into supramolecular chains along thebaxis. These chains are linked into a layer parallel to (10-1) by C—H...π interactions; layers stack with no specific interactions between them.

scholarly journals 12,15-Dimethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-1(18),2,4,6,11(16),12,14-heptaen-10-ol

IUCrData ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Alan J. Lough ◽  
Samuel Koh ◽  
William Tam
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Chair Conformation ◽  
Ring System ◽  
The Other ◽  
Pyran Ring ◽  
Compound C ◽  
Fused Ring ◽  
Fused Ring System

In the title compound, C19H18O2, the pyran ring is in a half-chair conformation. The fused ring system comprising the benzene and cyclohexene rings is essentially planar (r.m.s. deviation = 0.053 Å) and forms a dihedral angle of 27.95 (6)° with the other benzene ring. In the crystal, O—H...O hydrogen bonds connect the molecules into chains propagating along [001].

scholarly journals 7′-Amino-1′H-spiro[cycloheptane-1,2′-pyrimido[4,5-d]pyrimidin]-4′(3′H)-one

2012 ◽  
Vol 68 (8) ◽  
pp. o2546-o2546
Author(s):  
Shu Chen ◽  
Daxin Shi ◽  
Mingxing Liu ◽  
Jiarong Li
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Compound C ◽  
Dimensional Network

The title compound, C12H17N5O, was obtained by cyclocondensation of 2,4-diaminopyrimidine-5-carbonitrile with cycloheptanone. The tetrahydropyrimidine ring has a distorted boat conformation and the cycloheptane ring adopts a chair conformation. In the crystal, molecules are linkedviaN—H...O and N—H...N hydrogen bonds generating a three-dimensional network.

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