ESSESA: An expert system for structure elucidation from spectra. 6. Substructure constraints from analysis of 13C-NMR spectra

1995 ◽  
Vol 35 (6) ◽  
pp. 979-1000 ◽  
Author(s):  
Hong Huixiao ◽  
Han Yinling ◽  
Xin Xinquan ◽  
Shi Yufeng
Keyword(s):  
Expert System ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Nmr Spectra ◽  
13C Nmr Spectra

Stoffwechselprodukte von Mikroorganismen, XXIX [1] 13C-NMR-Spektren hochsubstituierter Naturstoffe vom Phthalid-Typ / Investigations on Metabolites of Microorganisms, XXIX [1] 13C NMR Spectra of Highly Substituted Natural Products of the Phthalide Type

1985 ◽  
Vol 40 (3) ◽  
pp. 426-428 ◽  
Author(s):  
Hans Achenbach ◽  
Andreas Mühlenfeld ◽  
Dieter Hunkler
Keyword(s):  
Natural Products ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Substituted Benzenes ◽  
C Nmr

Since the usual 13C shift increments are not applicable for very highly substituted benzenes, the 13C NMR spectra of 3-O-ethyl-cyclopolic acid (1) and 2 were studied and fully analyzed. These results were essential for the structure elucidation of a number of new highly substituted phthalides recently isolated from cultures of Aspergillus duricaulis [3].

Applying ILP to diterpene structure elucidation from 13C NMR spectra

1997 ◽  
pp. 41-54 ◽  
Author(s):  
Sašo Džeroski ◽  
Steffen Schulze-Kremer ◽  
Karsten R. Heidtke ◽  
Karsten Siems ◽  
Dietrich Wettschereck
Keyword(s):  
13C Nmr ◽  
Structure Elucidation ◽  
Nmr Spectra ◽  
13C Nmr Spectra

Diterpene Structure Elucidation from 13C NMR-Spectra with Machine Learning

1997 ◽  
pp. 207-225 ◽  
Author(s):  
Sašo Džeroski ◽  
Steffen Schulze-Kremer ◽  
Karsten R. Heidtke ◽  
Karsten Siems ◽  
Dietrich Wettschereck
Keyword(s):  
Machine Learning ◽  
13C Nmr ◽  
Structure Elucidation ◽  
Nmr Spectra ◽  
13C Nmr Spectra

Some Considerations Regarding the 1H and 13C Spectra of 4-(1-azulenyl)-2,6-bis(2-heteroaryl-vinyl)- pyrylium and Pyridinium and their Corresponding Pyridines

2018 ◽  
Vol 69 (1) ◽  
pp. 64-69
Author(s):  
Liviu Birzan ◽  
Mihaela Cristea ◽  
Constantin C. Draghici ◽  
Alexandru C. Razus
Keyword(s):  
Double Bond ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Pyridinium Salts ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Pyrylium Salts

The 1H and 13C NMR spectra of several 2,6-diheteroarylvinyl heterocycles containing 4-azulenyl moiety were recorded and their proton and carbon chemical shifts were compared with those of the compounds without double bond between the heterocycles. The influence of the nature of central and side heterocycles, molecule polarization and anisotropic effects were revealed. The highest chemical shifts were recorded for the pyrylium salts and the lowest at pyridines, but in the case of the pyridinium salts, the protons chemical shifts at the central heterocycle are more shielded due to a peculiar anisotropy of the attached vinyl groups.

13C-NMR spectra of substituted thiophenecarboxylic acids

1977 ◽  
Vol 42 (7) ◽  
pp. 2167-2170 ◽  
Author(s):  
I. Stibor ◽  
L. Radics ◽  
M. Janda ◽  
J. Šrogl ◽  
M. Němec
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra

13C NMR spectra of 1-aryl-ferrocenylethylenes

1986 ◽  
Vol 51 (3) ◽  
pp. 670-676 ◽  
Author(s):  
Eva Solčániová ◽  
Štefan Toma ◽  
Tibor Liptaj
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Substituent Effects ◽  
13C Nmr Spectra ◽  
Bridge Group ◽  
C Nmr ◽  
Electron Effects

13C NMR spectra of 18 ferrocene analogues of trans stilbenes (1-aryl-2-ferrocenylethylenes) were measured. It was found that bridge group weakens the transfer of the substituent electron effects into ferrocene nucleus, especially distinctly into 3',4'positions of cyclopentadienyl ring. The transfer of substituent effects into β-position of the bridge -CH=CH- is greater in derivatives studied by us than in stilbenes. Synthesis of 1-(4-dimethylaminophenyl)-2-ferrocenylethylene is described.

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