scholarly journals Betulin 3,28-di-O-tosylate

2014 ◽  
Vol 70 (8) ◽  
pp. o879-o880
Author(s):  
Uldis Peipiņš ◽  
Niks Freimanis ◽  
Dmitrijs Stepanovs ◽  
Anatoly Mishnev ◽  
Māris Turks
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Envelope Conformation ◽  
Compound C ◽  
Naturally Occurring ◽  
Dimensional Network ◽  
Cyclopentane Ring

The title compound, C44H62O6S2{systematic name: (1R,3aS,5aR,5bR,7aR,9S,11aR,11bR,13aR,13bR)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-3a-[(tosyloxy)methyl]icosahydro-1H-cyclopenta[a]chrysen-9-yl 4-methylbenzenesulfonate}, was obtained by tosylation of naturally occurring betulin. All the cyclohexane rings adopt chair conformations and the cyclopentane ring adopts a twisted envelope conformation, with the C atom bearing the tosylmethyl substituent forming the flap. In the crystal, molecules form a three-dimensional network through multiple weak C—H...O hydrogen bonds.

scholarly journals 14,15-Didehydrohellebrigenin

2012 ◽  
Vol 68 (6) ◽  
pp. o1614-o1615
Author(s):  
Tong Yu ◽  
Hai-Yan Tian ◽  
Xiao-Feng Yuan ◽  
Shu-Zhi Hu ◽  
Ren-Wang Jiang
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Lactone Ring ◽  
Three Dimensional ◽  
Membered Ring ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network ◽  
Hydroxy Groups

The title compound, C24H30O5, is the didehydro product of the steroid hellebrigenin (systematic name: 3β,5,14-trihydroxy-19-oxo-5β-bufa-20,22-dienolide). It consists of three cyclohexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclohexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Å and is β-oriented at the C atom of ring D to which it is attached. There is an O—H...O hydrogen bond in the molecule involving the hydroxy groups. In the crystal, O—H...O hydrogen bonds link the molecules into chains propagating along [010]. The chains are linked by C—H...O contacts into a three-dimensional network.

scholarly journals Crystal structure of 1,2,3,5-di-O-methylene-α-D-xylofuranose

2015 ◽  
Vol 71 (11) ◽  
pp. o889-o889
Author(s):  
Ioannis Tiritiris ◽  
Stefan Tussetschläger ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Cyclic Acetal ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network

The title compound, C7H10O5, was synthesized by reaction of D-xylose with paraformaldehyde. In the crystal, the central part of the molecule consists of a five-membered C4O ring with an envelope conformation, with the methine C atom adjacent to the O atom being the flap. The protected O atoms of both cyclic acetal groups are oriented so that the four chiral C atoms of the furanose part show anRconfiguration. C—H...O hydrogen bonds are present between adjacent molecules, generating a three-dimensional network.

scholarly journals 2-Acetonyl-2-hydroxyindan-1,3-dione

2009 ◽  
Vol 65 (6) ◽  
pp. o1209-o1209 ◽  
Author(s):  
Hoong-Kun Fun ◽  
Ching Kheng Quah ◽  
Mehtab Parveen ◽  
Raza Murad Ghalib ◽  
Sayed Hasan Mehdi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Membered Ring ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network

In the title compound, C12H10O4, the five-membered ring adopts an envelope conformation, with the Csp3atom at the flap [deviation = 0.145 (2) Å]. In the crystal structure, molecules are linked by intermolecular O—H...O and C—H...O hydrogen bonds, forming a three-dimensional network.

scholarly journals Deacetylcinobufalactam monohydrate

2014 ◽  
Vol 70 (6) ◽  
pp. o651-o652
Author(s):  
Hong-Jin Tang ◽  
Xiao-Feng Yuan ◽  
Hai-Yan Tian ◽  
Li-Jun Ruan ◽  
Ren-Wang Jiang
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Ammonium Acetate ◽  
Lactone Ring ◽  
Three Dimensional ◽  
Membered Ring ◽  
Epoxide Ring ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network

The title compound, C24H33NO4·H2O, the reaction product of deacetylcinobufagin with ammonium acetate, consists of three cyclohexane rings (A,BandC), one five-membered ring (D), one six-membered lactone ring (E) and an epoxide ring (F). The stereochemistry of the ring junctures areA/B cis,B/C trans,C/D cisandD/F cis. Cyclohexane ringsA,BandChave normal chair conformations. The five-membered ringDadopts an envelope conformation (with the C atom bearing the lactone ring as the flap) and the lactone ringEis planar. In the crystal, hydroxy and water O—H...O and amine N—H...O hydrogen bonds involving carbonyl, hydroxy and water O-atom acceptors link the molecules into a three-dimensional network.

scholarly journals Ethyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl)acetate

IUCrData ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Youssef Ramli ◽  
Rachida Akrad ◽  
Walid Guerrab ◽  
Jamal Taoufik ◽  
Mhamed Ansar ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Membered Ring ◽  
Axis Direction ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network ◽  
Oriented Parallel ◽  
Centrosymmetric Dimers

The five-membered ring of the title compound, C19H18N2O4, adopts an envelope conformation. In the crystal, pairwise N—H...O hydrogen bonds form centrosymmetric dimers which are connected into chains parallel to thec-axis direction by pairwise C—H...O hydrogen bonds. A second set of C—H...O hydrogen bonds links these chains into sheets oriented parallel to (100). A combination of additional C—H...O hydrogen bonds and C—H...π(ring) interactions combine the sheets into a three-dimensional network.

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.

scholarly journals Crystal structure of 5-[(4-carboxybenzyl)oxy]isophthalic acid

2016 ◽  
Vol 72 (8) ◽  
pp. 1219-1222
Author(s):  
Md. Serajul Haque Faizi ◽  
Musheer Ahmad ◽  
Akram Ali ◽  
Vadim A. Potaskalov
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Three Dimensional ◽  
Molecular Shape ◽  
Isophthalic Acid ◽  
Compound C ◽  
Dimensional Network ◽  
Benzene Rings

The molecular shape of the title compound, C16H12O7, is bent around the central CH2—O bond. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 87.78 (7)°. In the crystal, each molecule is linked to three others by three pairs of O—H...O hydrogen bonds, forming undulating sheets parallel to thebcplane and enclosingR22(8) ring motifs. The sheets are linked by C—H...O hydrogen bonds and C—H...π interactions, forming a three-dimensional network.

scholarly journals Crystal structure of 2-benzylamino-4-p-tolyl-6,7-dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile

2015 ◽  
Vol 71 (2) ◽  
pp. 192-194
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
S. Maharani ◽  
R. Ranjith Kumar ◽  
P. L. Nilantha Lakshman
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Pyridine Ring ◽  
Three Dimensional ◽  
Π Interactions ◽  
Compound C ◽  
Centroid Distance ◽  
Cyclopentane Ring ◽  
Ring Motif

The title compound, C23H21N3, comprises a 2-amino-3-cyanopyridine ring fused with a cyclopentane ring. The later adopts an envelope conformation with the central methylene C atom as the flap. The benzyl and andp-tolyl rings are inclined to one another by 56.18 (15)°, and to the pyridine ring by 81.87 (14) and 47.60 (11)°, respectively. In the crystal, molecules are linked by pairs of N—H...Nnitrilehydrogen bonds, forming inversion dimers with anR22(12) ring motif. The dimers are linked by C—H...π and π–π interactions [centroid–centroid distance = 3.7211 (12) Å], forming a three-dimensional framework.

scholarly journals Crystal structure of 2-bromo-1,4-dihydroxy-9,10-anthraquinone

2014 ◽  
Vol 70 (10) ◽  
pp. o1130-o1130 ◽  
Author(s):  
Wataru Furukawa ◽  
Munenori Takehara ◽  
Yoshinori Inoue ◽  
Chitoshi Kitamura
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Stacking Interactions ◽  
Compound C ◽  
Π Stacking ◽  
Dimensional Network

In an attempt to brominate 1,4-dipropoxy-9,10-anthraquinone, a mixture of products, including the title compound, C14H7BrO4, was obtained. The molecule is essentially planar (r.m.s. deviation = 0.029 Å) and two intramolecular O—H...O hydrogen bonds occur. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds, Br...O contacts [3.240 (5) Å], and π–π stacking interactions [shortest centroid–centroid separation = 3.562 (4) Å], generating a three-dimensional network.

scholarly journals 4-Fluoro-N-(4-hydroxybenzylidene)aniline

2014 ◽  
Vol 70 (8) ◽  
pp. o860-o860
Author(s):  
L. Jothi ◽  
G. Anuradha ◽  
G. Vasuki ◽  
R. Ramesh Babu ◽  
K. Ramamurthi
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Schiff Bases ◽  
Title Compound ◽  
Three Dimensional ◽  
Dihedral Angles ◽  
Axis Direction ◽  
Compound C ◽  
Dimensional Network ◽  
Phenyl Rings

In the title compound, C13H10FNO, the benzene ring planes are inclined at an angle of 50.52 (8)°. A characteristic of aromatic Schiff bases withN-aryl substituents is that the terminal phenyl rings are twisted relative to the plane of the HC=N link between them. In this case, the HC=N unit makes dihedral angles of 10.6 (2) and 40.5 (2)° with the hydroxybenzene and flurobenzene rings, respectively. In the crystal, O—H...N and C—H...F hydrogen bonds lead to the formation of chains along thec-andb-axis directions, respectively. C—H...π contacts link molecules alongaand these contacts combine to generate a three-dimensional network with molecules stacked along theb-axis direction.

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