Interpretation of proton magnetic resonance spectra by computer program. Enhanced elimination algorithm. Structural interpretation of PMR spectra by computer. First-order spectra. Comments

1975 ◽  
Vol 47 (8) ◽  
pp. 1487-1487
Author(s):  
D. H. Sleeman
Keyword(s):  
Magnetic Resonance ◽  
Computer Program ◽  
Proton Magnetic Resonance ◽  
Structural Interpretation ◽  
First Order ◽  
Elimination Algorithm ◽  
Pmr Spectra ◽  
Magnetic Resonance Spectra

Conversion of a 3-Oxaquadricyclane to a Substituted Cyclobutane. Preparation and Proton Magnetic Resonance Spectra of Four Stereoisomeric 1,2-Diacetyl-3,4-dicarbomethoxycyclobutanes

1971 ◽  
Vol 49 (4) ◽  
pp. 574-582 ◽  
Author(s):  
J. Laing ◽  
A. W. Mcculloch ◽  
D. G. Smith ◽  
A. G. Mcinnes
Keyword(s):  
Magnetic Resonance ◽  
Computer Program ◽  
Long Range ◽  
Trans Isomer ◽  
Proton Magnetic Resonance ◽  
Ring System ◽  
Spin Interactions ◽  
Selective Deuteration ◽  
Cyclobutane Ring ◽  
Magnetic Resonance Spectra

Reaction of l,5-dicarbomethoxy-2,4-dimethyl-3-oxaquadricyclane with water gave a mixture of cis,cis,cis- and cis,cis,trans-1,2-diacetyl-3,4-dicarbomethoxycyclobutanes. The latter on treatment with acid epimerized to the corresponding trans,trans,trans-isomer, whereas the former yielded the trans,trans, cis-epimer together with 3,10-dimethyl-3,10-epoxy-5,8-dioxo-4,9-dioxatricyclo[5.3.0.02,6]decane which contains a new bridged ring system. The structure and stereochemistry of each compound was derived from symmetry considerations as reflected in its p.m.r. spectrum, and was facilitated by selective deuteration experiments. Vicinal and long-range spin–spin interactions between the cyclobutane ring hydrogens were deduced from pertinent p.m.r. sub-spectra using the NMRIT–NMREN computer program.

CYCLOHEXANE COMPOUNDS: VI. NUCLEAR MAGNETIC RESONANCE SPECTRA OF SOME DERIVATIVES OF THE STEREOISOMERIC 3-BROMO-1,2-CYCLOHEXANEDIOLS AND THE 2-BROMO-1,3-CYCLOHEXANEDIOLS

1966 ◽  
Vol 44 (7) ◽  
pp. 775-780 ◽  
Author(s):  
R. A. B. Bannard
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Angular Distortion ◽  
Order Analysis ◽  
First Order ◽  
Nuclear Magnetic Resonance Spectra ◽  
Derivatives Of ◽  
Magnetic Resonance Spectra

First-order analysis of the 60 Mc.p.s. proton magnetic resonance spectra of 1α-methoxy-2β-acetoxy-3α-bromocyclohexane, 1α-methoxy-2α-acetoxy-3β-bromocyclohexane, 1α-methoxy-2β-bromo-3α-acetoxycyclohexane, 1α-methoxy-2α-bromo-3β-acetoxycyclohexane, and the corresponding diol diacetates confirmed the stereochemical interrelationships of substituents which were assigned previously on chemical grounds, and demonstrated that the compounds exist in chair conformations. The chemical shifts of the methoxy methyl and acetoxy methyl protons did not provide reliable criteria for the assignment of conformations to these substituents in this series. The coupling constants of the methine protons followed, in general, the pattern predicted by the Karplus equation, and the smaller J2,3 values observed in the cis,trans compounds relative to those in the trans,trans compounds are interpreted mainly on the basis of conformational equilibration, upon which is superimposed a small dihedral angular distortion or a remote substituent orientational effect.

The preparation of 2-Fluoro-5-nitrobenzonitrile and the proton magnetic resonance spectra of some compounds containing the N-(2-Cyano-4-nitrophenyl) group

1967 ◽  
Vol 20 (8) ◽  
pp. 1663 ◽  
Author(s):  
JFK Wilshire
Keyword(s):  
Amino Acids ◽  
Magnetic Resonance ◽  
Nitro Group ◽  
Proton Magnetic Resonance ◽  
Cyano Group ◽  
Aromatic Nucleus ◽  
Heteroaromatic Compounds ◽  
Magnetic Resonance Spectra

2-Fluoro-5-nitrobenzonitrile, an analogue of 1-fluoro-2,4- dinitrobenzene, in which the 2-nitro group has been replaced by a cyano group, has been prepared and made to react with several amines, amino acids, and NH-heteroaromatic compounds. The proton magnetic resonance spectra of some of the resultant N-(2-cyano-4-nitrophenyl) derivatives were compared with the spectra of the corresponding N-(2,4- dinitrophenyl) derivatives and furnish further evidence that the ortho nitro group of the latter derivatives is rotated out of the plane of the aromatic nucleus.

Investigation and Identification of the Bromination Products of Dimethoxyamphetamines

1976 ◽  
Vol 59 (5) ◽  
pp. 1162-1169
Author(s):  
Keith Bailey ◽  
Denise R Gagné ◽  
Richard K Pike
Keyword(s):  
Magnetic Resonance ◽  
Qualitative Analysis ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Infrared Spectra ◽  
Proton Magnetic Resonance ◽  
Positive Identification ◽  
Aromatic Bromination ◽  
Layer Chromatography ◽  
Magnetic Resonance Spectra

Abstract The qualitative analysis of the aromatic bromination products of the 6 isomeric dimethoxyamphetamines and their hydrochloride or hydrobromide salts is described. Their ultraviolet, mass, and proton magnetic resonance spectra are not sufficiently different for distinction but infrared spectra allow a positive identification to be made and reference spectra are provided for the bromination products of 2,4-, 2,5-, 2,6-, 4,5-, and 3,5-dimethoxyamphetamines. The application of gas-liquid and thin layer chromatography for the analysis of these products is discussed. The bromination of 2,3-dimethoxyamphetamine consistently gave mixtures which could not be separated satisfactorily; spectra are included for completeness of the comparison of products.

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