Proton magnetic resonance and infrared studies of the cis and trans isomers of a monosubstituted formanilide

1968 ◽  
Vol 72 (6) ◽  
pp. 2135-2141 ◽  
Author(s):  
Thomas H. Siddall ◽  
W. E. Stewart ◽  
A. L. Marston
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Infrared Studies ◽  
Cis And Trans

Conformations, configurations, and proton reactions of colbalt(III) complexes

1967 ◽  
Vol 20 (2) ◽  
pp. 257 ◽  
Author(s):  
DA Buckingham ◽  
L Durham ◽  
AM Sargeson
Keyword(s):  
Amino Acid ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Proton Magnetic Resonance ◽  
Proton Magnetic Resonance Spectroscopy ◽  
Proton Exchange ◽  
Resonance Spectroscopy ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Proton magnetic resonance spectroscopy allows the cis and trans isomers of [CoX2 en2] complexes to be distinguished. Some information has been obtained concerning the rate of chelate conformational interchange for cobalt-ethylenediamine, propylenediamine, N-methylethylenediamine, and malonate rings. For [Co(amino acid)en2]2+ complexes the diastereoisomeric pairs can be differentiated and the relative rates of CH and NH proton exchange have been observed for a variety of chelate rings including cobalt-amino acid, acetylacetonato, ethylenediamine, and malonato.

Morpholines: stereochemistry and preferred steric course of quaternization

1976 ◽  
Vol 54 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Alan J. Jones ◽  
C. P. Beeman ◽  
M. U. Hasan ◽  
A. F. Casy ◽  
M. M. A. Hassan
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Nmr Spectra ◽  
Deuterium Nmr ◽  
Free Energies ◽  
Trans Isomers ◽  
Methyl Substitution ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

The 13C magnetic resonance spectra of a series of methyl and phenyl substituted morpholines, their hydrochlorides, and methiodides have been determined. The effects of methyl substitution adjacent to oxygen and nitrogen are reasonably equivalent and substituent induced chemical shift parameters derived for the series show favorable agreement with those previously observed in both alicyclic and heterocyclic systems. Results for the cis and trans isomers of phendimetrazine (3,4-dimethyl-2-phenylmorpholine), confirm the preferred chair conformations and configurations cis-3-CH3, cis-2-phenyl (cis) and trans-3-CH3, cis-2-phenyl (trans) for these isomers. The preferred course of quaternization of nitrogen in these systems was determined as axial, using deuteriomethyliodide as a label. This 13C–2H technique relies on the observation of the γ-syn-axial effect and is clearly unambiguous and superior to other methods used in evaluating this mechanism. Product ratios and consequently free energies of this reaction were measured from proton and deuterium nmr spectra.

THE PROTON MAGNETIC RESONANCE SPECTRA OF CHRYSANTHEMUM ETHYL ESTER AND THE RELATED cis- AND trans-CHRYSANTHEMUMIC ACIDS

1962 ◽  
Vol 40 (5) ◽  
pp. 875-881 ◽  
Author(s):  
H. M. Hutton ◽  
T. Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Ethyl Ester ◽  
Proton Magnetic Resonance ◽  
Acid Ethyl Ester ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Magnetic Resonance Spectra

The high-resolution proton magnetic resonance spectra of a mixture of the cis and trans isomers of chrysanthemum monocarboxylic acid ethyl ester have been studied. The cis-chrysanthemumic and trans-chrysanthemumic acids spectra were obtained to facilitate the interpretation of the complex spectra of the ester. The percentage of the trans isomer in the chrysanthemum ester was measured to be 62.0 ± 1.1%. The cyclopropane proton spin coupling constants were found to be Jcis = 8.7 c.p.s. and Jtrans = 5.4 c.p.s., in reasonable agreement with Karplus' calculations of the dependence of coupling constants on the dihedral angle.

Concerning the mechanism of the addition of ethanesulfenyl chloride to 3,4-dihydro-2H-pyran

1968 ◽  
Vol 46 (7) ◽  
pp. 1093-1099 ◽  
Author(s):  
M. J. Baldwin ◽  
R. K. Brown
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Sulfur Dioxide ◽  
Resonance Spectrum ◽  
Trans Isomers ◽  
Initial Formation ◽  
Cis And Trans Isomers ◽  
Crude Mixture ◽  
The Stability ◽  
Cis And Trans

The nuclear magnetic resonance spectrum, at −40°, of the crude mixture obtained by the reaction of ethanesulfenyl chloride with 3,4-dihydro-2H-pyran at −40° clearly supports the view that the product is trans-2-chloro-3-ethylthiotetrahydropyran. The possibility that there is initial formation of 3-chloro-2-ethylthiotetrahydropyran followed by its rapid rearrangement to 2-chloro-3-ethylthiotetrahydropyran is ruled out because of the stability of 3-chloro-2-ethylthiotetrahydropyran to distillation under vacuum. The latter compound is obtained as a mixture of cis and trans isomers by the reaction of ethyl mercaptan with 5-chloro-3,4-dihydro-2H-pyran in the presence of sulfur dioxide.

Identification of cis- and trans-Cinnamoylcocaine in Illicit Cocaine Seizures

1973 ◽  
Vol 56 (5) ◽  
pp. 1199-1205 ◽  
Author(s):  
James M Moore
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Degradation Products ◽  
Mass Spectrometric ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Depth Analysis ◽  
Mass Spectrometric Identification ◽  
Cis And Trans ◽  
Chromatographic Isolation

Abstract During the in-depth analysis of illicit cocaine samples small amounts of other coca alkaloids and cocaine degradation products have been detected. One of these alkaloids, cinnamoylcocaine, has been found in more than half of the samples examined, usually in concentrations of 1% or less of the amount of cocaine present. The presence of cinnamoylcocaine, as its cis and trans isomers, was established by column partition chromatographic isolation of the isomers, followed by ultraviolet, infrared, nuclear magnetic resonance, and mass spectrometric identification.

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