Étude structurale d'un C-glycoside insaturé; le tri-O-acétyl-3,4,6-désoxy-2-α-D-thréo-hexéno-2-pyrannosyle benzène

1985 ◽  
Vol 63 (2) ◽  
pp. 491-494 ◽  
Author(s):  
Hélène Gillier-Pandraud ◽  
Rachid Brahmi ◽  
Véronique Bellosta-Dechavanne ◽  
Stanislas Czernecki
Keyword(s):  
Aromatic Ring ◽  
Crystalline State ◽  
Crystallographic Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Sugar Moiety ◽  
Nmr Data ◽  
Anomeric Carbon

The structure of 3,4,6-tri-O-acetyl-2-deoxy-α-D-threo-hexeno-pyranosyl benzene 1 has been determined by X-ray diffraction methods. Crystals of 1 are orthorhombic, space group P212121 with a = 22.946(10), b = 10.319(6), c = 7.684(4) Å, V = 1819.42 Å3, Z = 4, ρc = 1.27 g cm−3. The sugar moiety exhibits a half-chair 0H5 conformation in which the aromatic ring is quasi-axial. The anomeric carbon has the α. configuration. The comparison of the 1H nmr data with the crystallographic data established that, in solution, the conformation of 1 is very similar to that in the crystalline state.

Microbial Transformation of Glycyrrhetinic Acid by Colletotrichum lini AS3.4486

2015 ◽  
Vol 1120-1121 ◽  
pp. 877-881
Author(s):  
Chao Jun He ◽  
Yu Min Yang ◽  
Kong Yang Wu
Keyword(s):  
Single Crystal ◽  
Microbial Transformation ◽  
Glycyrrhetinic Acid ◽  
Conversion Product ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Sole Product ◽  
C Nmr

The biotransformation of 18β-glycyrrhetinic acid by Colletotrichum lini AS3.4486 was investigated. The conversion reaction was carried out for 72h, and the sole product was isolated by column chromatography and elucidated as 7β,15α-dihydroxy-18β-glycyrrhetinic acid by HR-ESI-MS, 1H-NMR , 13C-NMR and single–crystal X-ray diffraction. The crystal of the conversion product belongs to orthorhombic, space group P212121 with 11.828(1), 13.213(2), 19.606(2) Å , V = 3064.0 Å3, Z = 4. This study povides a new method for the synthesis of 7β,15α-dihydroxy-18β-glycyrrhetinic acid.

Spectroscopic and X-Ray Investigation of Cobalt(III) Complexes with 2-Oximinocarboxylic Acids

1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko
Keyword(s):  
Electronic Absorption Spectra ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Space Group ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
R Factors

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.

A clothes-peg-shaped binucleartrans-bis(2-aminotroponato)palladium(II) complex bearing pentamethylene spacers

2013 ◽  
Vol 69 (5) ◽  
pp. 503-505 ◽  
Author(s):  
Naruyoshi Komiya ◽  
Takeharu Kageyama ◽  
Masaya Naito ◽  
Takeshi Naota
Keyword(s):  
Single Crystal ◽  
Mass Spectroscopy ◽  
Crystalline State ◽  
Palladium Complex ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Π Stacking ◽  
Ft Ir ◽  
Molecular Unit

rac-Bis{μ-trans-2,2′-[pentane-1,5-diylbis(azanediyl)]ditroponato}dipalladium(II), [Pd2(C19H20N2O2)2], has been synthesized and fully characterized using single-crystal X-ray diffraction,1H NMR, FT–IR and mass spectroscopy. Thetranscoordination, vaulted structure andanticonformation have been unequivocally established from the X-ray diffraction studies. This is the first example of a bis(aminotroponato)palladium complex. In the crystalline state, the molecule has twofold symmetry and each molecular unit undergoes intermolecular offset π-stacking of the tropone rings to afford heterochiral interpenetrating dimers that are aligned in a lamellar manner with a herringbone packing motif.

Structure of isosilerolide, relative and absolute configuration of silerolide and lasolide - Sesquiterpenic lactones of new stereoisomeric type of eudesmanolides

1986 ◽  
Vol 51 (4) ◽  
pp. 903-929 ◽  
Author(s):  
Miroslav Holub ◽  
Miloš Buděšínský ◽  
Zdenka Smítalová ◽  
David Šaman ◽  
Urszula Rychłewska
Keyword(s):  
Absolute Configuration ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Chemical Correlation ◽  
The Absolute

On the basis of spectroscopic, particularly 1H NMR data, isosilerolide was assigned structure I, including the absolute configuration. The structure was confirmed by X-ray diffraction. Isosilerolide represents a new stereoisomeric type of natural eudesmanolides, characterized as 5βH, 6αH, 7αH, 10αCH3-eudesman-6,12-olide. As shown by the chemical correlation of isosilerolide (I) with silerolide (III) and lasolide (X), the latter two natural lactones belong to this stereoisomeric group of eudesmanolides. Analysis of models and 1H NMR data shows that structures of some eudesman-6,12-olides, published by other authors, should be corrected.

Structure of a pentacyclic triterpenyl angelate from Loeseliamexicana. 1H 2D-NMR data and stereochemistry

1989 ◽  
Vol 67 (12) ◽  
pp. 2071-2077 ◽  
Author(s):  
M. Jiménez E. ◽  
K. Velézquez ◽  
A. Lira-Rocha ◽  
A. Ortega ◽  
E. Díaz ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Parent Compound ◽  
2D Nmr ◽  
X Ray Diffraction ◽  
Pentacyclic Triterpene ◽  
Nmr Structure Determination ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Unambiguous Assignment

The total assignment of 1H NMR spectra of a pentacyclic triterpene from Loeseliamexicana was performed using selected 2D-NMR experiments (COSY, NOE). X-ray diffraction data were obtained from the parent compound as supplemental information to the NMR investigations. The data allowed for the unambiguous assignment of the structure and the stereochemistry of the title compound. Keywords: pentacyclic triterpene NMR, 2D NMR of terpenes, X-ray of triterpenes, triterpenyl angelate NMR, X-ray -2D NMR structure determination.

A solid state NMR and X-ray crystallographic investigation of dynamic disorder in solid tetrahydronaphthalene derivatives

1996 ◽  
Vol 74 (10) ◽  
pp. 1844-1851 ◽  
Author(s):  
Glenn A. Facey ◽  
Terrence J. Connolly ◽  
Corinne Bensimon ◽  
Tony Durst
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
X Ray Diffraction ◽  
Molecular Conformations ◽  
Dynamic Disorder ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Deuterated Analog ◽  
Naphthoic Acid

The solid state disorder of two tetrahydronaphthalene derivatives, N-methyl-N-methoxy-5,6,7,8-tetrahydro-1-naphthamide and 5,6,7,8-tetrahydro-1-naphthoic acid, was studied by solid state NMR and single crystal X-ray diffraction. The X-ray crystal structure of N-methyl-N-methoxy-5,6,7,8-tetrahydro-1-naphthamide was obtained at 123 K. It indicated the presence of two distinct molecular conformations. Solid state 13C CP/MAS NMR data using the dipolar dephasing technique revealed that the two conformations of the molecule are dynamically disordered, while solid state 2H NMR data, collected on a specifically deuterated analog, were used to determine the populations of each conformation as well as an apparent activation energy. Solid state NMR experiments were also used to show that 5,6,7,8-tetrahydro-1-naphthoic acid possesses the same type of dynamic disorder. Key words: deuterium NMR, solid state NMR, dynamic disorder. X-ray, tetrahydronaphthalene derivatives

Complexes of methylmercury(II) with 1-methylcytosine and crystal structure of μ-(1-methylcytosinato-N3,N4)bis(methylmercury(II)) nitrate

1981 ◽  
Vol 59 (15) ◽  
pp. 2290-2297 ◽  
Author(s):  
Leonardo Prizant ◽  
Roland Rivest ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Amino Group ◽  
Nitrate Salt ◽  
Acidic Media ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
R Factor ◽  
Nmr Data ◽  
Solid Complexes

Two types of solid complexes are isolated by reaction of CH3HgX (X = NO3 and ClO4) with 1-methylcytosine (MCy). The CH3Hg+ ion is probably bonded to N(3) in the [CH3Hg(MCy)]X compounds. Mercury binding to N(3) and the deprotonated amino group in [(CH3Hg)2(MCy—H)]X is confirmed by X-ray work on the nitrate salt. The crystals are orthorhombic, space group Pbca, with a = 12.014, b = 13.573, c = 16.353 Å, and Z = 8. The structure was refined on 962 independent reflections to an R factor of 0.038. The CH3Hg+ groups are arranged in a syn configuration and the angles around the mercury-bonded nitrogen atoms are severely distorted to prevent short Hg … Hg contacts. N(3)-coordination in the 1:1 complexes introduces minor changes in the infrared spectra, but the substitution of an amino proton in the 1:2 compounds produces important modifications. 1H nmr data in DMSO-d6 are reported for both types of compounds. This work emphasizes the important acidity enhancement experienced by the amino protons upon initial coordination to N(3), which facilitates further reaction of CH3Hg+ by proton displacement even in acidic media.

Structural Characterization Of Rh(Iii) Complexes Containing The Polypyridyl Ligands And Some Properties Of Their Derivatives

2001 ◽  
Vol 56 (8) ◽  
pp. 747-752 ◽  
Author(s):  
Mee Y. Kim ◽  
Won K. Seok ◽  
Heung N. Lee ◽  
Sung H. Han ◽  
Yongkwan Dong ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Chloride Complexes ◽  
Polypyridyl Ligands ◽  
X Ray ◽  
H Nmr ◽  
Rhodium Chloride ◽  
Nmr Data ◽  
Elemental Analyses ◽  
Rhodium Atom

The structures of the compounds [Rh(bpy)2(py)(Cl)](ClO4 )2 (2 (ClO4 )2) and [Rh(phen)2(py)- (Cl)](ClO4 )2 (7 -(ClO4 )2) were determined by single-crystal X-ray diffraction. Both complexes show a six-coordinate rhodium atom with two bpy or phen ligands in the cis configuration. The Rh-Cl distances are 2.334(3) and 2.323(2) Å, respectively. The bond angles N-Rh-Cl formed with the axially-positioned nitrogen atom are 174.4(2) and 173.8(2)°. The oxidation of aquo complexes, prepared from the corresponding rhodium chloride complexes, by two equivalents of Ce(IV) in 60% HCIO4 solution yields the corresponding mono-oxo products. All complexes have been identified and characterized by elemental analyses, IR, and 1H NMR data

1,2-Bis-(1-{3-pyridyl-}3-methyltriazen-3-yl)ethane: Synthesis and X-ray crystal structure

2004 ◽  
Vol 82 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Keith Vaughan ◽  
Elizabeth Turner ◽  
Hilary Jenkins
Keyword(s):  
Crystal Structure ◽  
Diazonium Salt ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Temperature Spectrum ◽  
X Ray ◽  
H Nmr ◽  
Antitumour Agent ◽  
Room Temperature Spectrum ◽  
Conventional Manner

3-Aminopyridine is diazotized in the conventional manner and the diazonium salt coupled with N,N ′-dimethylethylenediamine to afford the title compound (1), which is a potential antitumour agent. The compound has been characterized by spectroscopic methods. The 1H NMR spectrum shows evidence of rotational conformerism, from the observation of broadening of the N-methyl signals in the room-temperature spectrum. Low-temperature NMR spectra (down to 223 K) show the presence of three distinct rotamers. The crystal structure of 1,2-bis-(1-{3-pyridyl-}3-methyltriazen-3-yl)ethane (1) has been determined by single crystal X-ray diffraction analysis. The bis-triazene (1) exists as the "staggered" conformation in the solid state, with an "anti–anti" configuration around the N—N bond of the triazene units. The crystal structure of 1 is compared with the closely related bis-triazene 2 and also compared with the simple mono-triazene 3. Crystal data for 1, C14H18N8: orthorhombic, space group Pbca, a = 11.2550(8) Å, b = 8.8507(6) Å, c = 15.0069(10) Å, β = 90°, and V = 1494.91(18) Å3, for Z = 4.Key words: triazene, bis-triazene, pyridine, X-ray, VT NMR, diazonium coupling.

scholarly journals Synthesis and Molecular Structure of Chiral (2S, 5S)-tert-Butyl 3-Oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Tetsuji Moriguchi ◽  
Suvratha Krishnamurthy ◽  
Toru Arai ◽  
Akihiko Tsuge
Keyword(s):  
Single Crystal ◽  
High Resolution Mass Spectrometry ◽  
Amino Acid Ester ◽  
Ethyl Esters ◽  
X Ray Diffraction ◽  
Chiral Column ◽  
Orthorhombic Space Group ◽  
Chiral Compound ◽  
X Ray ◽  
H Nmr

The title compound (2S, 5S)-tert-butyl 3-oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate was synthesized as a chiral cyclic amino acid ester from the corresponding cis- and trans-5-hydroxypipecolic acid ethyl esters via an intramolecular lactonization reaction without using chiral catalyst or enzyme and without separation by chiral column chromatography. The chiral compound was characterized using 1H NMR spectroscopy and high-resolution mass spectrometry. Its exact structure was then determined via single crystal X-ray diffraction analysis of a single crystal obtained after recrystallization of the compound from ethyl acetate/diethyl ether. The crystal was found to be of the orthorhombic space group P212121 (No. 19, noncentrosymmetric, chiral) with a=9.6402(10) Å, b=9.7026(10) Å, c=12.2155(12) Å, Dcalc=1.3194 g/cm3, and a Flack parameter of 0.0(5) at 90 K. The compound has a bicyclo[2.2.2]octane structure comprised of lactone and piperidine groups.

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