Identification of substituted furyltetrazolyl acetates by means of 13C NMR spectrometry

1984 ◽  
Vol 49 (8) ◽  
pp. 1895-1899 ◽  
Author(s):  
Jan Světlík ◽  
Igor Goljer ◽  
Ľubomír Janda

13C NMR data of a series of 5-[5-(substituted phenyl)-2-furyl]-1- and -2-tetrazolyl acetates are presented. Examination of diagnostic resonances emphasizing particularly those arising from the tetrazole ring system enabled both isomers to be easily distinguished. The chemical shift increment for 5-(2-furyl)-1- and -2-tetrazolyl acetate unit has been deduced.

1979 ◽  
Vol 34 (11) ◽  
pp. 1334-1343 ◽  
Author(s):  
W. Storek ◽  
J. Sauer ◽  
R. Stößer

13C-NMR spectra of tetracene, rubrene, 1,3,5-tri-, penta-, and hexaphenylbenzene are reported. The discussion also includes the already known 13C-NMR data for diphenyl, 9,10-diphenyl-, 9,10-dibenzyl-, and 9,10-dimethyl-anthracene [1] as well as toluene. On the basis of CNDO/2 calculations different influences (diamagnetic and paramagnetic term, anisotropic contribution, ring current effect, geometry) on the chemical shift are analyzed for diphenyl and within the row benzene through tetracene


1999 ◽  
Vol 23 (3) ◽  
pp. 202-203
Author(s):  
Daniel A. Fletcher ◽  
Brian G. Gowenlock ◽  
Keith G. Orrell ◽  
David C. Apperley ◽  
Michael B. Hursthouse ◽  
...  

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.


2020 ◽  
Vol 15 (10) ◽  
pp. 1934578X2093378
Author(s):  
Josep Coll Toledano

The present review of NMR spectroscopic structural elucidation data of new compounds isolated from Scutellaria species is focused on the title compounds, displaying a peculiar 13-spiro feature. It contains a compilation of 1H and 13C NMR data of these diterpenoids grouped by similar substitution patterns. Comparing shielding effects pointed out not only the identity of some compounds (already reported) but also potential misassignments and convenient revisions to get unambiguous structural proposals.


2006 ◽  
Vol 1 (4) ◽  
pp. 1934578X0600100 ◽  
Author(s):  
Sebastião F. Palmeira Jünior ◽  
Lucia M. Conserva ◽  
José Maria Barbosa Filho

The present work is a review of the literature of clerodane diterpenes from Croton species. It contains a compilation of 13C NMR data of 83 of these diterpenoids and their biological activities. This review covers a period from 1969 to October 2005 and 224 references are cited.


1990 ◽  
Vol 68 (11) ◽  
pp. 2033-2038 ◽  
Author(s):  
Giovanna Barbarella ◽  
Massimo Luigi Capobianco ◽  
Luisa Tondelli ◽  
Vitaliano Tugnoli

The preferential protonation sites of the homo dimers deoxycytidylyl-(3′,5′)-deoxycytidine, thymidylyl-(3′,5′)-thymidine, and deoxyadenylyl-(3′,5′)-deoxyadenosine were established by nitrogen-15 and carbon-13 NMR in dimethyl sulfoxide, in the presence of varying amounts of CF3COOH. The nitrogen-15 NMR data show that in d(CpC) the capability of the two N3 nitrogens to accept the proton is slightly different. In d(TpT) and d(ApA) the protonation of the phosphate group leads to significant variations of the chemical shift of the carbons adjacent to phosphorus. Keywords: deoxydinucleotides, protonation, 15N and 13C NMR.


1978 ◽  
Vol 56 (13) ◽  
pp. 1836-1842 ◽  
Author(s):  
A. Gavin McInnes ◽  
Donald G. Smith ◽  
John A. Walter ◽  
Jeffrey L. C. Wright ◽  
Leo C. Vining ◽  
...  
Keyword(s):  

Analysis by 1H and 13C nmr spectrometry showed that caerulomycin D, a new metabolite isolated from S. caeruleus, possessed a novel ring system and had the structure (2S,3R,4R,4aS,10aS)-3,4,4a,10a-tetrahydro-4-hydroxy-3,4a-diniethoxy-2-methyl-9-(2-pyridyl)-2H-pyrano[3′,2′:5,6]-p-dioxino[2,3-c]pyridine-7-carboxaldenyde (E)-oxime.


2017 ◽  
Vol 13 ◽  
pp. 2478-2485 ◽  
Author(s):  
Przemysław J Boratyński

Scoring permutations of experimental chemical shift deviations and DFT/GIAO calculated deviations of isotropic shieldings for sets of four diastereomers can help to assign their relative configurations. This method was exercised on a set of diastereomeric Cinchona alkaloid derivatives, where 13C NMR data always identified the proper configuration. The presented approach is also an attempt to quantify the assignment by exclusion.


1976 ◽  
Vol 54 (10) ◽  
pp. 1660-1664 ◽  
Author(s):  
I. W. J. Still ◽  
N. Plavac ◽  
D. M. McKinnon ◽  
M. S. Chauhan

13C nmr data have been obtained for a series of 4-thiazoline-2-thiones. Substituent chemical shift (s.c.s.) effects for methyl and phenyl substitution have been collated and are discussed in comparison with s.c.s. effects in other heterocyclic systems. Some attempt has also been made to compare our data with those reported previously for the thiazoles and for some thiones in the isothiazole series.


2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1986265
Author(s):  
Mónica Díaz-Fernández ◽  
María I. Salazar ◽  
Pedro Joseph-Nathan ◽  
Eleuterio Burgueño-Tapia

The known diterpenoids horminone (1) and taxoquinone (2) as a mixture, and pure 6,7-dehydroroyleanone (7) were isolated from the aerial parts of not yet studied Salvia concolor Lamb. Although 1 and 2 are known, the 1H Nuclear Magnetic Resonance (NMR) data of their acetyl derivatives 4 to 6 are only partially described. Moreover, the 13C NMR data assignments for 4 and 6 show some inconsistencies and reveal better agreement with those we obtained for diastereoisomeric 3 and 5. Since stereochemical aspects were in doubt, it was considered as mandatory to unambiguously determine the absolute configuration of 3 to 6 using vibrational circular dichroism spectroscopy, which then allowed the complete 1H and 13C NMR chemical shift assignments of 4 to 6.


1982 ◽  
Vol 37 (4) ◽  
pp. 412-419 ◽  
Author(s):  
Bernd Wrackmeyer

11B and 13C NMR data of peralkylated nido-2,3,4,5-tetracarbahexaboranes(6) are reported. Application of selective heteronuclear triple resonance experiments 13C{1H,11B} enables to assign the structures of various isomers. The magnitude of the coupling constants 1J(11B11B), 1J(13C11B) and 1J(13C13C) is in accord with expectations based on the conception of bonding in carboranes. The comparison of δ11B and δ13C data of the nido- 2,3,4,5-tetracarboranes(6) with δ13C-data of corresponding non-classical carbocations shows the influence of charge upon the nuclear shielding of carbon in the latter.


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