(3E)-5-Hydroxy-3-[5-(hydroxymethyl)furan-2-ylmethylene]-1-benzofuran-2(3H)-one

2007 ◽  
Vol 63 (11) ◽  
pp. o4354-o4354
Author(s):  
Hong-Yan Ma ◽  
Ji Shi ◽  
Chang-Hong Wang ◽  
Zheng-Tao Wang
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Data ◽  
Furan Ring ◽  
Crystallographic Analysis ◽  
Relative Configuration ◽  
X Ray ◽  
H Nmr ◽  
Compound C ◽  
A Chain ◽  
C Nmr

The title compound, C14H10O5, was isolated from Senecio cannabifolius Less var. integrifolius aqueous extract. The structure was elucidated on the basis of spectroscopic data, including MS, 1H NMR and 13C NMR, and the relative configuration was confirmed by X-ray crystallographic analysis. The benzofuran ring is almost coplanar with the furan ring [dihedral angle = 10.47 (15)°]. A chain is formed through supramolecular R 2 2(10) synthons and three-centre hydrogen bonds.

Pd(II) and Pt(II) Complexes of 1,2-Bis(pyridin-2-yl)ethane-N,N'

1994 ◽  
Vol 49 (6) ◽  
pp. 844-848 ◽  
Author(s):  
A. McFarlane ◽  
J. R. Lusty ◽  
J. J. Fiol ◽  
A. Terrón ◽  
E. Molins ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Data ◽  
Low Energy ◽  
X Ray ◽  
H Nmr ◽  
Direct Bond ◽  
Structures And Properties ◽  
C Nmr

X-ray crystal structures and properties of the two Pd(II) and Pt(II) complexes [bpeH2][PdCl4] and [Pt(bpe)Cl2], [bpe = 1,2-bis(pyridin-2-yl)ethane] are described and correlated with the IR and 1H NMR/13C NMR spectroscopic data. In the case of the Pt(II) complex, the 1,2-bis(pyridin-2-yl)ethane is bound to the metal by the heterocycle nitrogen atoms but no direct bond is found in the case of the Pd(II) complex. The ligand exhibits low energy geometries in both compounds: the cis-conformation in the Pt(II) complex, and the transconformation in the Pd(II) complex

Synthesis and characterization of novel azo-embedded N-confused tetraphenylporphyrin

2009 ◽  
Vol 13 (02) ◽  
pp. 215-222 ◽  
Author(s):  
Motoki Toganoh ◽  
Takayoshi Hihara ◽  
Kentaro Yonekura ◽  
Yuichi Ishikawa ◽  
Hiroyuki Furuta
Keyword(s):  
Absorption Spectrum ◽  
Effective Interaction ◽  
Coupling Reaction ◽  
Crystallographic Analysis ◽  
Synthesis And Characterization ◽  
X Ray ◽  
H Nmr ◽  
Cis Isomer ◽  
C Nmr

A unique class of azo porphyrin, 5,10,15,20-tetraphenyl-21-phenylazo-(2-aza-21-carbaporphyrin 1, in which an azophenyl group is embedded in N -confused porphyrin, was synthesized and characterized by 1 H NMR, 13 C NMR, UV-vis absorption, MS, and X-ray crystallographic analysis. Synthesis of 1 was achieved through a coupling reaction of 21-amino N -confused tetraphenylporphyrin with nitrosobenzene and subsequent deoxygenation of resulting azoxy derivative with a trioxo rhenium(VII) N -fused porphyrinato catalyst. The azo-conjugate molecule was exclusively obtained as a trans-isomer and no isomerization to the cis-isomer was observed under thermal or photoirradiation. The absorption spectrum of 1 shows a moderate red-shift due to the effective interaction between the porphyrinic π-system and the connecting azophenyl group. Upon protonation, this effect is essentially lost as a result of removing degeneracy of LUMO and LUMO+1.

scholarly journals 1-Deacetoxy-1-oxocaesalmin

2014 ◽  
Vol 70 (6) ◽  
pp. o662-o662
Author(s):  
Juan Feng ◽  
Jian-Long Zhang ◽  
Rong-Rong Zhang ◽  
Li-Jun Ruan ◽  
Ren-Wang Jiang
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Furan Ring ◽  
Chair Conformation ◽  
Chain Structure ◽  
Membered Ring ◽  
Axis Direction ◽  
Compound C ◽  
A Chain

The title compound, C24H30O7, is a diterpenoid isolated from the seeds ofCaesalpinia minax. It consists of two cyclohexane rings (AandB), one unsaturated six-membered ring (C) and one furan ring (D). The stereochemistry of the ring junctures isA/B transandB/C trans. RingsAandBhave normal chair conformations whileCadopts a twisted half-chair conformation due to fusion to the furan ring which is planar [r.m.s. deviation = 0.0009 (2) Å]. In the crystal, hydroxyl O—H...Ocarbonylhydrogen bonds link the molecules into a chain structure extending along thea-axis direction.

Gelsevirine hydrochloride

2007 ◽  
Vol 63 (3) ◽  
pp. o1369-o1371
Author(s):  
Hai-Bin Han ◽  
Zhong Yuan ◽  
Kai Xiao ◽  
Min-Qin Chen ◽  
Liming Zhang
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Folk Medicine ◽  
Indole Alkaloid ◽  
Crystallographic Analysis ◽  
Terpenoid Indole Alkaloid ◽  
X Ray ◽  
Compound C

At 293 K, a crystalline terpenoid indole alkaloid, the title compound, C21H25N2O3 +·Cl−, has been isolated from Gelsemium elegans Benth, a Chinese folk medicine plant. Structural ambiguities have been resolved by the X-ray crystallographic analysis. Intramolecular C—H...O and intermolecular C—H...Cl, C—H...O and N—H...Cl hydrogen bonds help to stabilize the structure.

scholarly journals Crystal structure ofN′-[(E)-(1S,3R)-(3-isopropyl-1-methyl-2-oxocyclopentyl)methylidene]-4-methylbenzenesulfonohydrazide

2015 ◽  
Vol 71 (12) ◽  
pp. o904-o905 ◽  
Author(s):  
David Tymann ◽  
Dina Christina Dragon ◽  
Christopher Golz ◽  
Hans Preut ◽  
Carsten Strohmann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Title Compound ◽  
Membered Ring ◽  
Dihedral Angles ◽  
Relative Configuration ◽  
Bond Angles ◽  
Compound C ◽  
A Chain

The title compound, C17H24N2O3S, was synthesized in order to determine the relative configuration of the corresponding β-keto aldehyde. In the U-shaped molecule, the five-membered ring approximates an envelope, with the methylene C atom adjacent to the quaternary C atom being the flap, and the methyl and isopropyl substituents lying to the same side of the ring. The dihedral angles between the four nearly coplanar atoms of the five-membered ring and the flap and the aromatic ring are 35.74 (15) and 55.72 (9)°, respectively. The bond angles around the S atom are in the range from 103.26 (12) to 120.65 (14)°. In the crystal, molecules are linkedviaN—H...O hydrogen bonds, forming a chain along theaaxis.

Synthesis and crystal structures of a 3-acetylated (20S,24S)-ocotillol-type saponin and its C-24 epimer

2017 ◽  
Vol 73 (6) ◽  
pp. 464-469 ◽  
Author(s):  
Juan Liu ◽  
Yang-Rong Xu ◽  
Xing-Si An ◽  
Gui-Ge Hou ◽  
Qing-Guo Meng
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Dimensional Network ◽  
Crystal Packings ◽  
C Nmr

In order to study the in vivo protective effect on myocardial ischemia, (20S,24R)-epoxydammarane-12β,25-diol, (V), and (20S,24S)-epoxydammarane-12β,25-diol, (VI), were synthesized through a novel synthetic route. Two key intermediates, namely (20S,24R)-3-acetyl-20,24-epoxydammarane-3β,12β,25-triol, (III) [obtained as the hemihydrate, C32H54O5·0.5H2O, (IIIa), and the ethanol hemisolvate, C32H54O5·0.5C2H5OH, (IIIb), with identical conformations but different crystal packings], and (20S,24S)-3-acetyl-20,24-epoxydammarane-3β,12β,25-triol, C32H54O5, (IV), were obtained during the synthesis. The structures were confirmed by 1H NMR, 13C NMR and HRMS analyses, and single-crystal X-ray diffraction. Molecules of (IIIa) are extended into a two-dimensional network constructed with water molecules linked alternately through intermolecular O—H...O hydrogen bonds, which are further stacked into a three-dimensional network. Compound (IIIb) contains two completely asymmetric molecules, which are linked in a disordered manner through intermolecular C—H...O hydrogen bonds. While the crystal stacks in compound (IV) are linked via weak C—H...O hydrogen bonds, the hydrogen-bonded chains extend helically along the crystallographic b axis.

Stereoisomeric chiral 2,9-diazabicyclo[4.4.0.]decane-3,10-diones as models of dipeptide grouping: Synthesis, X-ray, IR, NMR and cd studies

1984 ◽  
Vol 49 (3) ◽  
pp. 712-742 ◽  
Author(s):  
Karel Bláha ◽  
Ahmed M. Farag ◽  
Dick VAN DER Helm ◽  
M. Bilayet Hossain ◽  
Miloš Buděšínský ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Stereospecific Synthesis ◽  
Cd Spectra ◽  
X Ray Diffraction ◽  
Relative Configuration ◽  
X Ray ◽  
H Nmr ◽  
Chemical Correlation ◽  
Cd Studies ◽  
C Nmr

Synthesis of the title optically active bicyclic dilactams I and II with cis- and trans-annelation of rings is described. The stereospecific synthesis started from (2R)-2-benzamido-2-(4-oxocyclohexyl)acetic acid ((-)-VI) whose absolute configuration was determined by chemical correlation with the known (2R)-2-amino-(4-hydroxyphenyl)acetic acid ((-)-IIIb). Relative configuration at the bridgehead atoms in I and II was assigned by 1H and 13C NMR spectroscopy and confirmed by X-ray diffraction analysis which showed the detailed conformation in crystal. According to the 1H NMR spectra in solution the trans-isomer II has the same configuration as in crystal whereas the cis-isomer I exists in two forms one of which is identical with that in crystal. This conformational analysis agrees also with the IR spectra, detecting an intramolecularly hydrogen-bonded conformation for IIbut no hydrogen bond for I. The CD spectra of both lactams were successfully interpreted using the exciton theory in the π-π region where it reflects the differences in the angles Φ and ψ (for I Φ = 110°, ψ = -143°; forII Φ = -145°, ψ = 162°). In the n-π transition region the interpretation was based on the quadrant rule and also inherent non-planarity of one of the amide groups in II.

scholarly journals 5-Amino-5-deoxy-2-C-hydroxymethyl-2,3-O-isopropylidene-L-lyxono-1,5-lactam

2007 ◽  
Vol 63 (3) ◽  
pp. o1409-o1411
Author(s):  
Michela Simone ◽  
George W. J. Fleet ◽  
Richard Bream ◽  
David J. Watkin
Keyword(s):  
Absolute Configuration ◽  
Catalytic Hydrogenation ◽  
Title Compound ◽  
Crystallographic Analysis ◽  
Starting Material ◽  
Relative Configuration ◽  
X Ray ◽  
Compound C ◽  
The Absolute

The relative configuration of the title compound, C9H14NO5, formed by catalytic hydrogenation of an azidolactone, has been established by X-ray crystallographic analysis. The absolute configuration was determined by the use of 2,3-O-isopropylidene-L-lyxono-1,4-lactone as the carbohydrate starting material.

scholarly journals Crystal structure of (E)-N′-{[(1R,3R)-3-isopropyl-1-methyl-2-oxocyclopentyl]methylidene}-4-methylbenzenesulfonohydrazide

2015 ◽  
Vol 71 (2) ◽  
pp. o99-o100 ◽  
Author(s):  
David Tymann ◽  
Dina Christina Dragon ◽  
Christopher Golz ◽  
Hans Preut ◽  
Carsten Strohmann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Title Compound ◽  
Membered Ring ◽  
Dihedral Angles ◽  
Relative Configuration ◽  
Axis Direction ◽  
Compound C ◽  
A Chain

The title compound, C17H24N2O3S, was synthesized in order to determine the relative configuration of the corresponding β-keto aldehyde. In the U-shaped molecule, the five-membered ring approximates an envelope with the methylene atom adjacent to the quaternary C atom being the flap. The dihedral angles between the four nearly coplanar atoms of the five-membered ring and the flap and the aromatic ring are 38.8 (4) and 22.9 (2)°, respectively. The bond angles around the S atom are in the range 104.11 (16)–119.95 (16)°. In the crystal, molecules are linkedviaN—H...O by hydrogen bonds, forming a chain along thea-axis direction.

scholarly journals Crystal structure of (E)-4-hydroxy-6-methyl-3-{1-[2-(4-nitrophenyl)hydrazinylidene]ethyl}-2H-pyran-2-one

2017 ◽  
Vol 73 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Kirandeep ◽  
Ahmad Husain ◽  
Pooja Negi ◽  
Girijesh Kumar ◽  
Ramesh Kataria
Keyword(s):  
Single Crystal ◽  
Crystal Packing ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Dehydroacetic Acid ◽  
Compound C ◽  
Ft Ir ◽  
C Nmr

The title compound, C14H13N3O5(HMNP), was synthesized by the simple condensation ofp-nitrophenylhydrazine with dehydroacetic acid (DHA) in a 1:1 molar ratio in ethanol. HMNP has been characterized by using FT–IR,1H and13C NMR and UV–Vis spectroscopic and single-crystal X-ray diffraction techniques. The crystal packing reveals strong hydrogen bonds between the NH group and the carbonyl O atom of dihydropyranone moiety, forming chains along [101]. The thermal stability of the synthesized compound was confirmed by thermogravimetric analysis and it was found to be stable up to 513 K. The UV–Vis spectrum shows the presence of a strong band at λmax394 nm.1H NMR and single-crystal X-ray analyses confirmed the presence of theenolform of the ligand and dominance over theketoform. The crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.3720 (19):0.6280 (19).

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