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 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 meso-4,4′-Difluoro-2,2′-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene)}diphenol

2013 ◽  
Vol 69 (2) ◽  
pp. o217-o217 ◽  
Author(s):  
Augusto Rivera ◽  
Diego Quiroga ◽  
Jaime Ríos-Motta ◽  
Monika Kučeraková ◽  
Michal Dušek
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Bond Forming ◽  
Compound C ◽  
Dimensional Network ◽  
Rabbit Ear ◽  
Hydroxy Groups

In the crystal structure of the title compound, C21H24F2N2O2, there are two intramolecular O—H...N hydrogen bonds involving the N atoms of the imidazolidine ring and the hydroxy groups. The crystal studied was amesocompound obtained by the reaction of the aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.18,17.02,7.011,16]cosane with 4-fluorophenol. The imidazolidine ring has a twisted conformation with a CH—CH—N—CH2torsion angle of 44.99 (14)° and, surprisingly, the lone pairs of the N atoms are disposed in asynisomerism, making the title compound an exception to the typical `rabbit-ear effect' in 1,2-diamines. In the crystal, molecules are linkedviaC—H...F hydrogen bonds, forming chains along thec-axis direction. These chains are linkedviaanother C—H...F hydrogen bond, forming 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 Crystal structure of β-D,L-psicose

2015 ◽  
Vol 71 (5) ◽  
pp. o289-o290 ◽  
Author(s):  
Tomohiko Ishii ◽  
Genta Sakane ◽  
Akihide Yoshihara ◽  
Kazuhiro Fukada ◽  
Tatsuya Senoo
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Cell Volume ◽  
Title Compound ◽  
Three Dimensional ◽  
Compound C ◽  
Dimensional Network ◽  
Hydroxy Groups

The title compound, C6H12O6, a C-3 position epimer of fructose, was crystallized from an aqueous solution of equimolar mixture of D- and L-psicose (1,3,4,5,6-pentahydroxyhexan-2-one,ribo-2-hexulose, allulose), and it was confirmed that D-psicose (or L-psicose) formed β-pyranose with a2C5(or5C2) conformation. In the crystal, an O—H...O hydrogen bond between the hydroxy groups at the C-3 and C-2 positions connects homochiral molecules into a column along thebaxis. The columns are linked by other O—H...O hydrogen bonds between D- and L-psicose molecules, forming a three-dimensional network. An intramolecular O—H...O hydrogen bond is also observed. The cell volume of racemic β-D,L-psicose [763.21 (6) Å3] is almost the same as that of chiral β-D-psicose [753.06 Å3].

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.

4-Bromo-N-(3,4-methylenedioxybenzyl)aniline

2007 ◽  
Vol 63 (11) ◽  
pp. o4404-o4404 ◽  
Author(s):  
Shu-Ping Yang ◽  
Li-Jun Han ◽  
Da-Qi Wang ◽  
Hai-Tao Xia
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Network Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Compound C ◽  
Dimensional Network

In the title compound, C14H12BrNO2, the molecules are linked by one C—H...Br hydrogen bond, so forming a C(13) chain running parallel to the [010] direction, and these chains are linked by further C—H...π and C—H...Br hydrogen bonds, resulting in a three-dimensional network structure.

scholarly journals Crystal structure of β-D,L-fructose

2015 ◽  
Vol 71 (10) ◽  
pp. o719-o720 ◽  
Author(s):  
Tomohiko Ishii ◽  
Tatsuya Senoo ◽  
Akihide Yoshihara ◽  
Kazuhiro Fukada ◽  
Genta Sakane
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Equimolar Mixture ◽  
Compound C ◽  
Dimensional Network ◽  
Hydroxy Groups

The title compound, C6H12O6, was crystallized from an aqueous solution of equimolar mixture of D- and L-fructose (1,3,4,5,6-pentahydroxyhexan-2-one,arabino-hexulose or levulose), and it was confirmed that D-fructose (or L-fructose) formed β-pyranose with a2C5(or5C2) conformation. In the crystal, two O—H...O hydrogen bonds between the hydroxy groups at the C-1 and C-3 positions, and at the C-4 and C-5 positions connect homochiral molecules into a column along theaaxis. The columns are linked by other O—H...O hydrogen bonds between D- and L-fructose molecules, forming a three-dimensional network.

scholarly journals Crystal structure of 4-{[(1H-1,2,4-triazol-1-yl)methyl]sulfanyl}phenol

2014 ◽  
Vol 70 (10) ◽  
pp. o1106-o1106
Author(s):  
Yong-Le Zhang ◽  
Chuang Zhang ◽  
Wei Guo ◽  
Jing Wang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Three Dimensional ◽  
Triazole Ring ◽  
Hydrogen Bond Interactions ◽  
Compound C ◽  
Dimensional Network

In the title compound, C9H9N3OS, the plane of the benzene ring forms a dihedral angle of 33.40 (5)° with that of the triazole group. In the crystal, molecules are linked by O—H...N hydrogen bonds involving the phenol –OH group and one of the unsubstituted N atoms of the triazole ring, resulting in chains along [010]. These chains are further extended into a layer parallel to (001) by weak C—H...N hydrogen-bond interactions. Aromatic π–π stacking [centroid–centroid separation = 3.556 (1) Å] between the triazole rings links the layers into a three-dimensional network.

scholarly journals (3aR*,8bR*)-3a,8b-Dihydroxy-1-(4-methylphenyl)-2-methylsulfanyl-3-nitro-1,8b-dihydroindeno[1,2-b]pyrrol-4(3aH)-one

2014 ◽  
Vol 70 (3) ◽  
pp. o279-o280
Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
R. Ranjith Kumar ◽  
V. Jeyachandran ◽  
P. L. Nilantha Lakshman
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Compound C ◽  
Dimensional Network ◽  
Independent Molecules ◽  
Hydroxy Groups

The asymmetric unit of the title compound, C19H16N2O5S, contains four independent molecules (A,B,CandD), with two molecules (BandD) displaying disorder in their methylsulfanyl groups [occupancy ratios of 0.797 (11):0.203 (11) and 0.85 (2):0.15 (2)]. The nitro groups are twisted slightly out of the planes of the 2-pyrroline rings to which they are bonded with dihedral angles of 10.17 (1), 8.01 (1), 9.44 (1) and 8.87 (1)° in moleculesA,B,CandD, respectively. The 2-pyrroline rings are almost orthogonal to the attached tolyl rings, forming dihedral angles of 73.44 (1), 81.21 (1), 88.18 (8) and 73.94 (1)° for moleculesA,B,CandD, respectively. A weak intramolecular O—H...O interaction is observed in moleculesBandC. The two hydroxy groups in each molecule are involved in intermolecular O—H...O hydrogen bonding. In the crystal, molecules are connectedviaO—H...O and C—H...O hydrogen bonds, forming a complex three-dimensional network.

scholarly journals Redetermined structure of oxaline: absolute configuration using Cu Kα radiation

2012 ◽  
Vol 68 (6) ◽  
pp. o1626-o1626 ◽  
Author(s):  
Peng Qu ◽  
Zhi-Yong Wu ◽  
Wei-Ming Zhu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Absolute Configuration ◽  
Title Compound ◽  
Three Dimensional ◽  
Compound C ◽  
Dimensional Network ◽  
Absolute Structure ◽  
Atomic Coordinates

In the title compound, C24H25N5O4, the stereogenic C atom bonded to three N atoms and one C atom has an S configuration and its directly bonded neighbour has an R configuration. An intramolecular N—H...O hydrogen bond supports the near coplanarity of the two C3N2-five-membered rings [dihedral angle = 5.64 (10)°]. In the crystal, molecules are linked by N—H...N hydrogen bonds, forming a C(8) chain propagating in [001]. The chains are connected by C—H...O interactions, generating a three-dimensional network. The previous study [Nagel et al. (1974). Chem. Commun. pp. 1021–1022] did not establish the absolute structure and no atomic coordinates were published or deposited.

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