13C Nuclear Magnetic Resonance Spectra of Organic Sulfur Compounds: Cyclic Sulfides, Sulfoxides, Sulfones, and Thiones

1975 ◽  
Vol 53 (19) ◽  
pp. 2880-2890 ◽  
Author(s):  
M. S. Chauhan ◽  
I. W. J. Still
Keyword(s):  
Chemical Shift ◽  
Chemical Shifts ◽  
Limited Data ◽  
Organic Sulfur Compounds ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Chemical Shift Data ◽  
Derivatives Of ◽  
Shift Data ◽  
Methyl Phenyl

13C Chemical shift data have been obtained for more than 50 thiochromanone and related sulfoxide and sulfone derivatives. The assignments of the various resonances in the most important of these have been made using the limited data already available and also by comparison with certain model compounds, such as thioanisole, diphenyl sulfide, and the corresponding sulfoxides and sulfones.Within each of these three series and in a fourth which comprises derivatives of thiochromone, including three α, β-unsaturated thiones, we have examined the effects on 13C chemical shift of substitution at various positions in the thiochromanone skeleton. Among the substituents examined in this context are methyl, phenyl, methoxyl, bromine, and carbomethoxyl. Attempts to compare the 13C chemical shifts for the thiochromanone series with those in a few oxygen containing analogs and in a small number of structurally similar analogs are also discussed.

Carbon-13 Nuclear Magnetic Resonance Spectra of Isothiazole, 1,2-Dithiole, and 1,3-Dithiole Derivatives

1975 ◽  
Vol 53 (6) ◽  
pp. 836-844 ◽  
Author(s):  
N. Plavac ◽  
I. W. J. Still ◽  
M. S. Chauhan ◽  
D. M. McKinnon
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Carbonyl Compounds ◽  
Heterocyclic Compounds ◽  
Chemical Shifts ◽  
Conjugated Systems ◽  
Nuclear Magnetic Resonance Spectra ◽  
Chemical Shift Data ◽  
Shift Data

Carbon-13 chemical shift data have been obtained for a number of isothiazole, benzo[c]isothiazole, 1,2-dithiole, and 1,3-dithiole derivatives. A number of these compounds are thiones and the chemical shifts of the C=S carbons are discussed in the light of recent attempts to predict such chemical shifts from those of the analogous carbonyl compounds. Comparisons of substituent chemical shift (s.c.s.) effects in these heterocyclic compounds with those in simpler aromatic or conjugated systems have been made and additivity correlations tested in a number of cases.

The chemistry of pyrrolic compounds. LV. 13C chemical shift data for the isomeric protoporphyrins

1984 ◽  
Vol 37 (2) ◽  
pp. 335 ◽  
Author(s):  
RJ Abraham ◽  
PS Clezy ◽  
Lv Thuc
Keyword(s):  
Chemical Shift ◽  
Side Chain ◽  
Methine Carbon ◽  
Chemical Shift Data ◽  
13C Chemical Shift ◽  
Derivatives Of ◽  
Shift Data

The 13C n.m.r, spectra of the 15 isomeric protoporphyrin dimethyl esters have been determined. Measurements were made on the zinc chelate derivatives of the porphyrins in the presence of pyrrolidine and assignments are given for the side chain and methine carbon atoms.

Carbon-13 nuclear magnetic resonance spectra of N-, O-, and S-methylated uracil and thiouracil derivatives

1978 ◽  
Vol 56 (5) ◽  
pp. 725-729 ◽  
Author(s):  
Ian W. J. Still ◽  
Nick Plavac ◽  
David M. McKinnon ◽  
Mohinder S. Chauhan
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Chemical Shift ◽  
General Type ◽  
Chemical Shifts ◽  
Pyrimidine Derivatives ◽  
Aromatic Substituent ◽  
Nuclear Magnetic Resonance Spectra ◽  
Derivatives Of ◽  
Thiouracil Derivatives ◽  
C Nmr

13C nmr chemical shifts have been recorded for a number of uracil, thiouracil, and pyrimidine derivatives. These data are discussed in relation to what is known of the lactam–lactim tautomerism in such systems and possible correlations of chemical shifts with normal aromatic substituent chemical shift parameters. The chemical shifts for the CH3 groups in simple methylated derivatives of uracil are very characteristic of the site of methylation and should prove useful as a tool for assigning structures to alkylated derivatives of this general type.

Nuclear magnetic resonance spectra, stereochemistry, and conformation of flavan derivatives

1964 ◽  
Vol 17 (6) ◽  
pp. 632 ◽  
Author(s):  
JW Clark-Lewis ◽  
LM Jackman ◽  
TM Spotswood
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Heterocyclic Ring ◽  
Coupling Constant ◽  
Nuclear Magnetic Resonance Spectra ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Chemical-shift and coupling-constant data for protons in 68 flavan derivatives are reported. Coupling-constant data for interactions involving the 2-, 3-, and 4-protons have been used to define the configuration of the 2-, 3-, and 4-substituents and the conformation of the heterocyclic ring. It is shown that chemical-shift data for protons of the heterocyclic ring and of 3- and 4-acetoxyl groups are of little value in stereochemical studies. Analysis of the absorptions of the aromatic protons shows that N.M.R. is useful for determining the oxygenation pattern in rings A and B.

scholarly journals N 6-Trimethyl-lysine metabolism. Structural identification of the metabolite 3-hydroxy-N6-trimethyl-lysine

1980 ◽  
Vol 188 (2) ◽  
pp. 521-527 ◽  
Author(s):  
Raymond F. Novak ◽  
Terrence J. Swift ◽  
Charles L. Hoppel
Keyword(s):  
Molecular Structure ◽  
Chemical Shift ◽  
Functional Group ◽  
Group Analysis ◽  
Resonance Spectroscopy ◽  
13C Nuclear Magnetic Resonance ◽  
Chemical Shift Data ◽  
Functional Group Analysis ◽  
13C Chemical Shift ◽  
Shift Data

1H and 13C nuclear-magnetic-resonance spectroscopy and functional-group analysis were used to determine the molecular structure of an isolated metabolite (IIb) of trimethyl-lysine as 3-hydroxy-N6-trimethyl-lysine, an important intermediate in the conversion of trimethyl-lysine into trimethylammoniobutyrate and carnitine [Hoppel, Cox & Novak (1980) Biochem. J.188, 509–519]. Functional-group analysis revealed the presence of a primary amine and reaction of metabolite (IIb) with periodate yielded 4-N-trimethylammoniobutyrate as a product, showing 2,3-substitution on the molecule and suggesting that the 3-substitution on the molecule may be an alcohol ([unk]CH–OH), amine ([unk]CH[unk]–NH2) or carbonyl ([unk]C=O) functional group. 1H integration ratios, 1H and 13C chemical-shift data and 1H and 13C signal multiplicities from the sample (IIb) were used to complete the identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. For example, the proton multiplet at δ 4.2p.p.m. and doublet at δ 4.1p.p.m., positions representative of amine or alcohol substitution on methylene carbon atoms, integration ratios of 1:1:2:9:4 and a positive ninhydrin test suggest 3-hydroxy-N6-trimethyl-lysine as the molecular structure for metabolite (IIb). 13C chemical-shift data obtained from the sample (IIb) and compared with several model compounds (trimethylammoniohexanoate, trimethyl-lysine and 3-hydroxylysine) resulted in generation of the spectrum of the metabolite and allowed independent identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. The 1H spectrum of erythro- and threo-3-hydroxylysine are presented for comparison, and the 1H and 13C n.m.r. spectra of the erythro-isomer support this analysis.

scholarly journals A computerized approach to the analysis of oligosaccharide structure by high-resolution proton n.m.r

1984 ◽  
Vol 223 (1) ◽  
pp. 129-143 ◽  
Author(s):  
E F Hounsell ◽  
D J Wright ◽  
A S R Donald ◽  
J Feeney
Keyword(s):  
Sialic Acid ◽  
High Resolution ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Oligosaccharide Structure ◽  
Chemical Shift Data ◽  
Computer Library ◽  
Shift Data

The 500 MHz proton-n.m.r. spectra of 21 oligosaccharides, predominantly of the lacto-N and lacto-N-neo series and their derivatives containing non-reducing terminal fucose, sialic acid or N-acetylgalactosamine and reduced-end hexitol or hexosaminitol, were examined with 2H2O as solvent. The chemical-shift data obtained from analysis of the spectra were collated with data from other laboratories who have used 250-500 MHz n.m.r. in the analysis of secreted and chemically synthesized oligosaccharides and of the O- and N-linked chains of glycoproteins. A referenced computer library was constructed that includes the chemical shifts of monosaccharides within oligosaccharide sequences that make up the majority of the carbohydrate structures found in mammalian glycoproteins. Examples are given of the computerized interrogation of this library for the assignment of possible structures of unknown oligosaccharides.

17O nuclear magnetic resonance spectroscopic study of substituted phthalic anhydrides and phthalides

1987 ◽  
Vol 65 (6) ◽  
pp. 1214-1217 ◽  
Author(s):  
David W. Boykin ◽  
Alfons L. Baumstark ◽  
Margaret M. Kayser ◽  
Chantal M. Soucy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Carbonyl Groups ◽  
Chemical Shift Data ◽  
The Relationship ◽  
Electronic Character ◽  
Shift Data ◽  
Phthalic Anhydrides

17O chemical shift data (natural abundance) for 3-substituted phthalic anhydrides and 4- and 7-substituted phthalides in acetonitrile at 75 °C are reported. Steric interactions of substituents ortho to the carbonyl groups result in deshielding effects (9–22 ppm) relative to parent compounds regardless of the electronic character of the substituents. Factors contributing to the deshielding effects are discussed. The relationship between 17O chemical shifts and regiochemistry of the phthalic anhydrides is discussed.

Substituent effects on the 13C chemical shifts of monosubstituted twistanes

1977 ◽  
Vol 55 (17) ◽  
pp. 3161-3165 ◽  
Author(s):  
Helmut Beierbeck ◽  
John K. Saunders
Keyword(s):  
Chemical Shift ◽  
Substituent Effect ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
13C Chemical Shifts ◽  
Bond Interaction ◽  
Chemical Shift Data ◽  
Shift Data ◽  
Deshielding Effect

The 13C chemical shift data for some hydroxy, chloro, bromo, and oxo twistane derivatives are presented and compared to the shifts observed in corresponding adamantanes. The substituent effect at the α and β carbons is more pronounced in twistanes than in adamantanes. The substituent shift induced at an antiperiplanar γ carbon is shown to depend on the presence or absence of 1,3-diaxial hydrogen–hydrogen interactions between the substituted and γ carbons. If such an interaction is present the effect is of shielding whereas if it is absent, the effect is of deshielding. The deshielding effect appears to occur via a through bond interaction.

scholarly journals 1H and 13C Nuclear Magnetic Resonance Spectroscopy of Some Derivatives of Nitro Sugars

1973 ◽  
Vol 51 (11) ◽  
pp. 1797-1800 ◽  
Author(s):  
N. Gurudata ◽  
F. J. M. Rajabalee
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Addition Reaction ◽  
Chemical Shifts ◽  
Resonance Spectroscopy ◽  
13C Nuclear Magnetic Resonance ◽  
Derivatives Of

Eight 2,3-dideoxy-2-amino-3-nitrosugar derivatives have been obtained by an elimination–addition reaction on the α and β anomers of methyl-4,6-O-benzylidene-3-deoxy-3-nitro-glucopyranoside-2-acetate. P.m.r. is used to show that the compounds exist in the CE conformation. 13C.m.r. data are presented for three anomeric pairs. Trends in the C-13 chemical shifts are found to be similar to those reported in other studies of carbohydrates. Exceptions in direction and magnitude of chemical shift differences are discussed.

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