scholarly journals 13C magnetic resonance spectra of some isoquinoline alkaloids and related model compounds

1976 ◽  
Vol 54 (14) ◽  
pp. 2252-2260 ◽  
Author(s):  
Donald W. Hughes ◽  
Herbert L. Holland ◽  
David B. MacLean

The natural abundance 13C nuclear magnetic resonance spectra of a number of isoquinoline alkaloids and related model compounds have been recorded. In almost all cases comparison of the spectra of the alkaloids with those of the model compounds has permitted unambiguous assignment of the alkaloid carbon resonances. The ability of 13C nmr spectroscopy to distinguish between diastereomeric pairs of both protoberberine and phthalideisoquinoline alkaloids has been demonstrated.

1977 ◽  
Vol 55 (18) ◽  
pp. 3304-3311 ◽  
Author(s):  
Donald W. Hughes ◽  
Bala C. Nalliah ◽  
Herbert L. Holland ◽  
David B. MacLean

The natural abundance 13C nuclear magnetic resonance spectra of a number of spirobenzylisoquinoline alkaloids and related model compounds have been recorded. The carbon resonances of the alkaloids were assigned by comparison with the spectra of other isoquinoline alkaloids and with those of the model compounds. It has been shown that 13C nmr spectroscopy may be used to differentiate between diastereomers in this series.


1965 ◽  
Vol 18 (4) ◽  
pp. 531 ◽  
Author(s):  
WE Hillis ◽  
DHS Horn

From an examination of the nuclear magnetic resonance spectra, optical rotations, and other properties of a number of flavonoid C-glycosides, their acetates, and related model compounds, it is concluded that vitexin, bayin, puerarin, and isohemiphloin are C-β-D-glucosides with the sugar substituent in the 8-position of the flavonoid nucleus. Hemiphloin and saponaretin are two of the corresponding 6-substituted compounds. In hemiphloin and isohemiphloin the phenyl B ring has the equatorial configuration.


1979 ◽  
Vol 57 (23) ◽  
pp. 3168-3170 ◽  
Author(s):  
Henk Hiemstra ◽  
Hendrik A. Houwing ◽  
Okko Possel ◽  
Albert M. van Leusen

The 13C nmr spectra of oxazole and eight mono- and disubstituted derivatives have been analyzed with regard to the chemical shifts and the various carbon–proton coupling constants of the ring carbons. The data of the parent oxazole are compared with thiazole and 1-methylimidazole.


1973 ◽  
Vol 51 (22) ◽  
pp. 3812-3819 ◽  
Author(s):  
D. R. Bundle ◽  
H. J. Jennings ◽  
Ian C. P. Smith

The 13C n.m.r. spectra of the 2-acetamido-2-deoxy-D-hexoses and some 3-O-acetyl and 1-phosphate derivatives are assigned and discussed. To facilitate the interpretation of the spectra, an initial assignment of the resonances in the spectrum of 2-acetamido-2-deoxy-D-glucose was required. For this purpose, both the 3-2H and 4-2H derivatives of this acetamido-hexose were synthesized. These syntheses are reported together with those of 2-acetamido-3-O-acetyl-2-deoxy-D-glucose and 2-acetamido-2-deoxy α- and β-D-glucose-1-phosphate. These model compounds were used to study substituent effects related to the 2-acetamido-2-deoxy-D-hexose-containing polysaccharide antigens of N. meningitides.


1979 ◽  
Vol 57 (4) ◽  
pp. 367-376 ◽  
Author(s):  
Pierre Lachance ◽  
S. Brownstein ◽  
Arthur M. Eastham

The identification of aliphatic hydrocarbons containing multiple asymmetric centers can be difficult because of the complexity of the nmr spectra and because in capillary chromatography the diastereomers may be resolved to varying degrees. We suggest that the most effective method for identifying such hydrocarbons is through the pattern of retention times developed by the mixture of diastereomers on a suitable capillary glc column.This paper presents the results of some studies of a series of alkanes having the general form C2H5—(CH—CH3)n—R, where n = 1 to 4, and includes the syntheses and 13C nmr spectra of the compounds.


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