Sur une nouvelle méthode de synthèse de δ-lactones cyclopenténiques

1986 ◽  
Vol 64 (4) ◽  
pp. 831-836 ◽  
Author(s):  
Jean Claude Caille ◽  
Michel Farnier ◽  
Roger Guilard ◽  
André Aubry ◽  
Claude Lecomte
Keyword(s):  
Mass Spectrometry ◽  
Carbon Atom ◽  
X Ray ◽  
Nmr Data ◽  
C Nmr

Synthesis of two cyclopentenic δ-lactones, 1,3,4,4a,5,6-hexahydrocyclopenta[c]pyran-1-one and its analogue possessing a cyclopentenyl group bonded to the carbon atom 4a is described, starting from the cyclopentanone or cyclopentylidene cyclopentanone. The remarkable reactivity of the tosylhydrazones allows transformation of these compounds into substituted cyclopentenes, which lead to δ-lactones by cyclization. The conditions of cyclization depend on the nature of the cyclopentanone. The structure of the two δ-lactones is established by 1H and 13C nmr data, mass spectrometry, and, in one case, by X-ray analysis.

Syntheses, Spectroscopy And Crystal Structures Of (R)-N-(1-Aryl-Ethyl)Salicylaldimines And [Rh{(R)-N-(1-Aryl-Ethyl)Salicylaldiminato}(η4-Cod)] Complexes

2007 ◽  
Vol 62 (6) ◽  
pp. 807-817 ◽  
Author(s):  
Mohammed Enamullah ◽  
A.K.M. Royhan Uddin ◽  
Anne-Christine Chamayou ◽  
Christoph Janiak
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Schiff Bases ◽  
Structure Determination ◽  
Chelate Ring ◽  
Optical Rotation ◽  
X Ray ◽  
Mononuclear Complexes ◽  
Chiral Schiff Base ◽  
C Nmr

Condensation of salicylaldehyde with enantiopure (R)-(1-aryl-ethyl)amines yields the enantiopure Schiff bases (R)-N-(1-aryl-ethyl)salicylaldimine (HSB*; aryl = phenyl, 2-methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl (4), 4-bromophenyl (5), 2-naphthyl). These Schiff bases readily react with dinuclear (acetato)(η4-cycloocta-1,5-diene)rhodium(I), [Rh(μ-O2CMe)(η4-cod)]2, to afford the mononuclear complexes, cyclooctadiene-((R)-N-(1-aryl-ethyl)salicylaldiminato-κ2N,O)- rhodium(I), [Rh(SB∗)(η4-cod)] (SB* = deprotonated chiral Schiff base = salicylaldiminate; aryl = phenyl (7), 2-methoxyphenyl, 4-methoxyphenyl, 4-bromophenyl, 2-naphthyl). The complexes have been characterized by IR, UV/vis, 1H/13C NMR and mass spectrometry, optical rotation as well as by single-crystal X-ray structure determination for 4, 5 and 7. The structure of 5 shows C-Br· · ·π contacts. Compound 7 is only the second example of a Rh(η4-cod) complex with a six-membered Rh-N,O-chelate ring

scholarly journals Simple Methylcadmium Alkoxides

2007 ◽  
Vol 62 (10) ◽  
pp. 1339-1342 ◽  
Author(s):  
Surajit Jana ◽  
Tania Pape ◽  
Norbert W. Mitzel
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Molecular Formula ◽  
Equimolar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses ◽  
Solid State Structures ◽  
Structural Aspects ◽  
C Nmr

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.

Crystal structure of 3-chlorobenzo[b]thiophene-2-carbonyl chloride

2009 ◽  
Vol 2009 (7) ◽  
pp. 437-439 ◽  
Author(s):  
Sara Tarighi ◽  
Alireza Abbasi ◽  
Sara Zamanian ◽  
Alireza Badiei ◽  
Mahmood Ghoranneviss
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Cinnamic Acid ◽  
Thionyl Chloride ◽  
Structure Determination ◽  
X Ray ◽  
Packing Structure ◽  
H Nmr ◽  
Carbonyl Chloride ◽  
C Nmr

3-Chlorobenzo[b]thiophene-2-carbonyl chloride was synthesised from cinnamic acid and thionyl chloride. The single crystal X-ray structure determination confirmed the earlier proposed structure and the product was further characterised by 1H NMR, 13C NMR and mass spectrometry. The X-ray structure determination revealed two sets of symmetry related molecules along the b-axis that are loosely connected by relatively weak CH…π ( 3.626, 3.628 Å) interactions, giving rise to two infinite chains. The packing structure is dominated by Van der Waals forces between these chains. No significant π–π interactions are found in the crystal structure.

Tautomerism in 3{5}-(dimethoxyphenyl)pyrazoles

1996 ◽  
Vol 52 (4) ◽  
pp. 746-752 ◽  
Author(s):  
M. A. Halcrow ◽  
H. R. Powell ◽  
M. J. Duer
Keyword(s):  
Hydrogen Bond ◽  
Nmr Spectroscopy ◽  
Solvate Water Molecule ◽  
X Ray ◽  
Nmr Data ◽  
Tautomeric Forms ◽  
Oxygen Donor ◽  
Intramolecular Hydrogen ◽  
Pyridinic N ◽  
C Nmr

The single-crystal X-ray structures of 3{5}-(2′,5′-dimethoxyphenyl)pyrazole (HI) and the hemihydrate of 3 {5}-(3/,4′-dimethoxyphenyl)pyrazole (IV) have been determined. Compound (HI) exists purely as the 5-substituted prototropomer in the crystal; the pyrazole pyrollic N—H proton is involved in a three-way hydrogen bond, involving an intramolecular contact with a methoxy oxygen donor and an intermolecular interaction to the pyridinic N atom of a neighbouring molecule, forming discrete hydrogen-bonded dimers. There is no evidence of degenerate proton transfer within the dimeric units from CPMAS 13C NMR spectroscopy, in contrast to other known pyrazoles that associate in this manner. In (IV).1/2H2O, however, the pyrrolic proton is disordered over both N(1) and N(2) via hydrogen bonding to the solvate water molecule. CPMAS 13C NMR spectroscopy shows that the prototropic disorder in (IV).1/2H2O is static at temperatures up to 370 K. Solution 1H and 13C NMR data in DMSO-d 6 show that for both (HI) and (IV) the 3- and 5-substituted tautomeric forms are similarly populated in this solvent, suggesting both that the intramolecular hydrogen bond in (HI) has been disrupted and that the two tautomers of (HI) and (IV) are close in energy.

A new type of crown ether. III. Triethylene glycolic diester of naphthalene dithioglycolic acid

1983 ◽  
Vol 61 (8) ◽  
pp. 1756-1759
Author(s):  
Lidia Prajer-Janczewski ◽  
Krystyna Rudolk ◽  
Tadeusz Lis ◽  
Marian Janczewski ◽  
Janina Biskup
Keyword(s):  
Mass Spectrometry ◽  
Crown Ether ◽  
Crystalline State ◽  
Structural Investigation ◽  
X Ray ◽  
New Type ◽  
C Nmr

The structure of 2,7-(11,22-diono-12, 15,18.21-tetroxa-9,24-dithia)-hexadecylene-naphthalene was investigated by 1H and 13C nmr and mass spectrometry. An X-ray structural investigation indicated the dissymmetric ansa structure of this compound in the crystalline state.

Pseudozoanthoxanthins from gold coral

1979 ◽  
Vol 57 (13) ◽  
pp. 1707-1711 ◽  
Author(s):  
Robert E. Schwartz ◽  
Mark B. Yunker ◽  
Paul J. Scheuer ◽  
Tor Ottersen
Keyword(s):  
Deep Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Data ◽  
Derivatives Of ◽  
C Nmr

From a deep water Pacific zoanthid, Gerardia sp., we have isolated two new fluorescent nitrogenous pigments, derivatives of tetrazacyclopentazulene. The first was characterized by uv, 1H and 13C nmr data, and by X-ray diffraction; the second by interconversion.

Oxidative coupling of naphtho-9-crown-3 ether: X-ray crystal structure and solution and solid-state NMR analysis of the dimer

2001 ◽  
Vol 79 (10) ◽  
pp. 1505-1510 ◽  
Author(s):  
G W Buchanan ◽  
M F Rastegar ◽  
G PA Yap ◽  
A Moghimi ◽  
M Ghandi
Keyword(s):  
Solid State ◽  
Oxidative Coupling ◽  
Solid State Nmr ◽  
Nmr Analysis ◽  
Oxidative Dimerization ◽  
Nmr Spectrum ◽  
X Ray ◽  
Nmr Data ◽  
Group A ◽  
C Nmr

Treatment of naphtho-9-crown-3 ether with FeCl3 and aqueous H2SO4 generates bis-naphtho-9-crown-3 ether in ca. 30% yield. This compound crystallizes in the monoclinic P21/n space group; a = 9.2004(9), b = 18.0868(17), and c = 13.2078(13) Å, β = 97.799(2)° and Z = 4. 1H and 13C NMR data have been obtained in solution, and the solid-state 13C NMR spectrum is included for comparison. A chemical shift range of ca. 12 ppm has been found for the oxygenated aliphatic carbons in the solid state, in contrast to the 3 ppm range in the solution 13C NMR spectrum. These results are discussed in terms of the torsional environments of the carbon sites in the crystal structure.Key words: crown ether, stereochemistry, oxidative dimerization.

The Structure And Tautomerism Of Cyameluric Acid*

2006 ◽  
Vol 61 (8) ◽  
pp. 975-978 ◽  
Author(s):  
Jörg Wagler ◽  
Nadia E. A. El-Gamel ◽  
Edwin Kroke
Keyword(s):  
Single Crystal ◽  
Keto Form ◽  
X Ray ◽  
Nmr Data ◽  
Almost All ◽  
Derivatives Of ◽  
Theoretical Results ◽  
C Nmr

The single crystal X-ray structure of the DMSO solvate of cyameluric acid C6N7O3H3 ·3DMSO, 2b’ has been determined. The results show that the most stable tautomer of solid cyameluric acid is the tri-keto form 2b with C3h symmetry. 1H and 13C NMR data indicate that this isomer is also present in solution, with slow interchange of the N-H protons. This confirms previous theoretical results although almost all derivatives reported in the literature are derivatives of the tri-hydroxy tautomer 2a

Reactivity of diosmacycles: complementary syntheses and structure Of [(µ-η1,η2-CHCH2)OS2(CO)8][BF4]

1995 ◽  
Vol 73 (7) ◽  
pp. 1003-1009 ◽  
Author(s):  
R.G. Ball ◽  
Gong Y. Kiel ◽  
William A. Kiel ◽  
Josef Takats ◽  
Friedrich-Wilhelm Grevels
Keyword(s):  
Solid State ◽  
Traditional View ◽  
Cationic Complex ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Excellent Yield ◽  
Nmr Data ◽  
Hydride Abstraction ◽  
C Nmr

The vinyl-bridged cationic complex, [(µ-CHCH2)Os2(CO)8][BF4] (3), is obtained readily and in excellent yield either via hydride abstraction from octacarbonyl diosmacyclobutane, (µ-η1,η1-CH2CH2)Os2(CO)8 (1), or via protonation of octacarbonyl diosmacyclobutene, (µ-η1,η1-CHCH)Os2(CO)8 (2). It is argued that the 1H and 13C NMR data of complex 3 are consistent with the traditional view of bonding in µ-alkenyl complexes, involving substantial σ,π donation. The solid state X-ray structure of the complex lends support for this formulation. Complex 3 crystallizes in the orthorhombic space group, P212121, with a = 12.128(2) Å, b = 14.151(3) Å, c = 9.248(3) Å, V = 1587 Å3, and Z = 4. The final R and Rw values are 0.032 and 0.038, respectively. Keywords: µ-vinyl, diosmacycles, X-ray structure.

Synthesis and Single Crystal X-Ray Structure of Ethyl 2-(1,3-Benzoxazol- 2-yl)-5-oxo-3-(4-toluidino)-2,5-dihydro-4-isoxazolecarboxylate

2007 ◽  
Vol 62 (5) ◽  
pp. 705-710 ◽  
Author(s):  
Ali Souldozi ◽  
Jabbar Khalafy ◽  
Ahmad Poursattar Marjani ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Structure Determination ◽  
Single Crystal Structure ◽  
Crystal Structure Determination ◽  
X Ray ◽  
C Nmr

Abstract Ethyl 5-oxo-3-(4-toluidino)-2,5-dihydro-4-isoxazolecarboxylate was prepared from the reaction of diethyl 2-(4-toluidinocarbothioyl)malonate with hydroxylamine. Its reaction with 2- chlorobenzoxazole gave the corresponding N-substituted isoxazolone. The structure of the final product 4 was confirmed by IR, 1H and 13C NMR spectroscopy and mass spectrometry, and by X-ray single crystal structure determination.

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