Use of two-dimensional correlation between2H quadrupolar splittings and13C CSA's for assignment of NMR spectra in chiral nematics

2004 ◽  
Vol 6 (6) ◽  
pp. 1080-1084 ◽  
Author(s):  
Olivier Lafon ◽  
Philippe Berdagué ◽  
Philippe Lesot
Keyword(s):  
Nmr Spectra ◽  
Two Dimensional ◽  
Quadrupolar Splittings

Studies of the neutral trisaccharides of goat (Capra hircus) colostrum and of the one- and two-dimensional 1H and 13C NMR spectra of 6′-N-acetylglucosaminyllactose

1994 ◽  
Vol 262 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Tadasu Urashima ◽  
William A. Bubb ◽  
Michael Messer ◽  
Yuhnagi Tsuji ◽  
Yasuko Taneda
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Capra Hircus ◽  
13C Nmr Spectra ◽  
Two Dimensional ◽  
1H And 13C Nmr ◽  
The One

scholarly journals Competitive Diels–Alder and ene addition of N-arylmaleimides to 7-dehydrocholesteryl acetate

1992 ◽  
Vol 70 (11) ◽  
pp. 2730-2744 ◽  
Author(s):  
William J. Leigh ◽  
Donald W. Hughes ◽  
D. Scott Mitchell
Keyword(s):  
Molecular Mechanics ◽  
Nmr Spectra ◽  
Benzene Solution ◽  
Diels Alder ◽  
Spectroscopic Techniques ◽  
Two Dimensional ◽  
A Minor ◽  
C Nmr ◽  
Alder Adduct ◽  
Ene Addition

Thermolysis of N-phenyl, N-para-biphenyl, and N-para, para′-terphenylmaleimide with 7-dehydrocholesteryl acetate in benzene solution at 200 °C yields mixtures of four cycloadducts in relative yields that are essentially independent of the maleimide substituent. The three major products are those of ene addition to C7 of the steroid with abstraction of the proton at C9 or C14. The α-endo-Diels-Alder adduct is formed as a minor product. The structures of the adducts have been elucidated on the basis of one- and two-dimensional 1H and 13C NMR spectroscopic techniques, including homonuclear 1H decoupling, NOE, 1H–1H COSY, heteronuclear 1H–13C shift correlation, and TOCSY 2-D experiments, and the results of molecular mechanics (MMX) calculations. The combination of these techniques has made it possible to almost completely assign the 1H and 13C NMR spectra for two of the ene adducts and the Diels–Alder adduct from reaction of 7-dehydrocholesteryl acetate with N-phenyl maleimide.

Structural studies of digitoxin and related cardenolides by two-dimensional NMR

1990 ◽  
Vol 68 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Torbjörn Drakenberg ◽  
Peter Brodelius ◽  
Deane D. McIntyre ◽  
Hans J Vogel
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Chair Conformation ◽  
Coupling Constants ◽  
Two Dimensional ◽  
Structural Studies ◽  
Solution Conformation ◽  
Phase Sensitive ◽  
Multiple Relay ◽  
C Nmr

The 1H and 13C NMR spectra of the cardenolides digitoxigenin, digoxigenin, digitoxin, and mono- and bis-digitoxigenin digitoxosides have been completely assigned by two-dimensional NMR spectroscopy. The techniques used include phase-sensitive COSY, multiple relay COSY, and carbon–proton correlation (HETCOR and HMQC) spectra. Various aspects of the solution conformation of the steroid moiety of digitoxin and digoxigenin could be determined from coupling constants and NOE difference experiments and they are indicative of an all-chair conformation. The carbohydrate rings in digitoxin and the mono- and bis-digitoxigenin digitoxosides are also in the chair conformation. Keywords: cardenolides, digitoxigenin, digitoxin, 2-dimensional NMR, conformational analysis.

Two-dimensional NMR spectra of 17?-(1-aziridinylmethyl)-5?-androstan-17?-ol

1988 ◽  
Vol 24 (11) ◽  
pp. 1212-1216
Author(s):  
A. �. Aliev ◽  
A. A. Fomichev ◽  
A. N. Sova ◽  
I. M. Gella ◽  
R. G. Kostyanovskii
Keyword(s):  
Nmr Spectra ◽  
Two Dimensional
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