Mixed aromatic-aliphatic acetals; Their preparation, 1H and 13C-NMR spectra and hydrogenolysis by ethereal solution of chloroalane

1981 ◽  
Vol 46 (11) ◽  
pp. 2912-2923 ◽  
Author(s):  
Jiří Dušek ◽  
Vladimír Sklenář ◽  
Jaroslav Jonas
Keyword(s):  
Vinyl Ether ◽  
Nmr Spectra ◽  
Relative Rate ◽  
Substituted Phenols ◽  
1H And 13C Nmr ◽  
H Nmr ◽  
Ethereal Solution ◽  
Rate Determining Step ◽  
Relative Rate Constants ◽  
C Nmr

The corresponding p-X-phenylisobutyl acetals to acetaldehyde (I), 2-(p-X-phenoxy)tetrahydropyrans (II), 2-(p-X-phenoxy)tetrahydrofurans (III), and cyclohexyl(p-X-phenyl)acetals of acetaldehyde (IV) were prepared by addition of p-X-substituted phenols to isobutyl vinyl ether, 2,3-dihydro-4H-pyran, 2,3-dihydrofuran, and cyclohexyl vinyl ether, respectively. The structures of acetals I-IV were confirmed by their 1H and 13C NMR spectra. Diastereotopic protons of the methylene and geminal methyl groups are anisochronous in the 1H NMR spectra of acetals I. 13C NMR spectra of acetals IV demonstrate anisochronous behaviour of cyclohexane ring diastereotopic carbon atoms. The constants σp+ for several groups calculated using 13C NMR spectra are: 1-isobutoxy-1-ethoxy- (-0.56), 2-tetrahydropyranyloxy- (-0.58), 2-tetrahydrofuryloxy- (-0.59), and 1-cyclohexyloxy-(1-ethoxy) (-0.57). Experimental relative rate constants of hydrogenolysis of acetals I and II by ethereal solution of chloroalane yield best correlations with σp+ constants of the substituent X, providing the values ρ = 2.61 and ρ = -1.09 for compounds of the series I and II, respectively. The importance of these results for finding the rate determining step of the studied reaction is discussed.

scholarly journals 1H- und C-NMR-Spektren von Methoxy-substituierten Äthylenen / 1H and 13C NMR Spectra of Methoxy-substituted Ethylenes

1976 ◽  
Vol 31 (1) ◽  
pp. 35-38 ◽  
Author(s):  
M. Herberhold ◽  
G. O. Wiedersatz ◽  
C. G. Kreiter
Keyword(s):  
Charge Distribution ◽  
Vinyl Ether ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether ◽  
Cis And Trans ◽  
C Nmr

The charge distribution in the methoxy -substituted olefins of the series ethylene, methyl vinyl ether, 1,1-dimethoxyethylene, cis- and trans-dimethoxyethylene, tetramethoxyethylene, is discussed on the basis of the 1H and 13C NMR spectra

1H and 13C NMR study of (X-phenyl)-5-nitro-2-furylvinyl ethers

1980 ◽  
Vol 45 (12) ◽  
pp. 3557-3563 ◽  
Author(s):  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Daniel Végh
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Furan Ring ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
H Nmr ◽  
Nmr Study ◽  
Hammett Σ Constants ◽  
C Nmr

Reaction of 5-nitro-2-furylvinyltrimethylammonium bromide with substituted phenolates gave (E)- and (Z)-(X-phenyl)-5-nitro-2-furylvinyl ethers. The preffered s-cis and s-trans orientations of the furan ring in Z and E isomers, respectively, were determined by 1H NMR spectroscopy. To study the extent of p-π conjugation, 13C NMR spectra of compounds under investigation have also been measured and interpreted. Chemical shifts for ethylenic carbons and protons were correlated with Hammett σ constants.

Conformational structure of ethylene glycol dibenzoate. Vibrational and NMR spectra

1981 ◽  
Vol 46 (8) ◽  
pp. 1913-1929 ◽  
Author(s):  
Bohdan Schneider ◽  
Pavel Sedláček ◽  
Jan Štokr ◽  
Danica Doskočilová ◽  
Jan Lövy
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectra ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Conformational Structure ◽  
Infrared And Raman Spectra ◽  
H Nmr ◽  
Liquid States ◽  
Crystalline Forms ◽  
C Nmr

It was found that three crystalline forms of ethylene glycol dibenzoate can be prepared. Infrared and Raman spectra of these three forms, as well as of the glassy and liquid states, were measured. From 3JHH coupling constants obtained by analysis of the 13C satellite band of the -CH2- group in 1H NMR spectra, and from the 3JCH coupling constants of the -CO.O.CH2- fragment obtained by analysis of the carbonyl band in 13C NMR spectra it was found that in the liquid state the -CH2-CH2- group exists predominantly in the gauche conformational structure, and the bonds C-O-C-C assume predominantly a trans orientation. The results of the analysis of NMR and vibrational spectra were used for the structural interpretation of conformationally sensitive bands in vibrational spectra of ethylene glycol dibenzoate.

1H and 13C NMR spectra of 2,2’-disubstitutedtrans-azobenzenes suitable for preparation of metallized azo dyes

1991 ◽  
Vol 56 (10) ◽  
pp. 2160-2168 ◽  
Author(s):  
Josef Jirman
Keyword(s):  
Nmr Spectra ◽  
Electron Pair ◽  
Phenyl Group ◽  
Aprotic Solvents ◽  
1H And 13C Nmr ◽  
Predominant Form ◽  
Rapid Equilibrium ◽  
Dipolar Aprotic Solvents ◽  
Free Electron Pair ◽  
C Nmr

The 1H and 13C NMR spectra have been measured of six trans-azobenzenes substituted at 2 and 2’ positions with substituents favourable for complex formation with a metal (OH, NH2, NHCOCH3, COOH). From the standpoint of NMR such substituted trans-azobenzenes are present in solution in a rapid equilibrium following from rotation around the bond between C-1 of phenyl group and N atom of azo linkage. The predominant form has the substituent in the syn-position with respect to the free electron pair of the nearer azo nitrogen atom. The equilibrium is affected by dipolar aprotic solvents (such as hexadeuteriodimethyl sulfoxide) by decreasing the presence of the predominant form by 1 to 11%.

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

1995 ◽  
Vol 60 (4) ◽  
pp. 619-635 ◽  
Author(s):  
Václav Křeček ◽  
Stanislav Hilgard ◽  
Miloš Buděšínský ◽  
Alois Vystrčil
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Coupling Constants ◽  
Side Chain ◽  
Oxidation Reactions ◽  
H Nmr ◽  
Complete Assignment ◽  
Nmr Techniques ◽  
Intramolecular Association ◽  
C Nmr

A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1H NMR, 13C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1H and 13C NMR spectra are discussed.

scholarly journals A Natural Triglyceride from the Methanol Root Extract of Cyphostemma Adenocaule (Steud. Ex A. Rich.) Wild & R.B.Drumm

2020 ◽  
Author(s):  
Abdulbasit Haliru Yakubu ◽  
Iliya Ibrahim ◽  
Abdulqadir bukar bababe ◽  
Hassan Yesufu ◽  
mohammed Garba Tom
Keyword(s):  
Mobile Phase ◽  
Nmr Spectra ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Solvent System ◽  
Root Extract ◽  
H Nmr ◽  
Signal Peak ◽  
Methylene Group ◽  
C Nmr

<p><i>Cyphostemma adenocaule </i>(Steud. ex A. Rich.) is one of the specie plant that belongs to the family vitacea. In this study, Trilinolein was isolated and characterized from the methanol root extract of the plant. Column chromatography over silica gel granules as the stationary phase and eluted with a mobile phase mixture of n-Hex-EtA; EtA-CHCL3 and CHCL<sub>3</sub>-MeOH with gradient increasing polarity, followed by a second column using saphadex-LH20 and 100% MeOH as stationary and mobile phase vehicle respectively. TLC was developed with EtA 15: CHCL3<sub> </sub>8: MeOH 4: H<sub>2</sub>O 1 as solvent system; sprayed with 10% H<sub>2</sub>SO<sub>4 </sub>,Vanillin-sulphuric acid, and/ or Polyethylene glycol PEG and heat for spot detection and confirmation of bioactive principles. Compound CA1 was obtained and purified with CHCL3 to give a yellow semi-solid compound (0.23g). The <sup>1</sup>H-NMR spectra showed 9 different signals; a signal peak of a glycerol (-C<b>H<sub>2</sub></b>OCOR-) moiety on the first α-C chain and on the third αʹ-C at 4.143-4.187ppm and 4.296-4.325ppm respectively, while that of a β glycerol (-C<b>H</b>COR-) at 5.286ppm. Signals of an allylic methylene group at 2.023-2.035ppm, Olefenic hydrogen group at signal peak of 5.362ppm and a diallylic methylene group at signal 2.790ppm were also observed. In the <sup>13</sup>C NMR spectra of compound CA1, 57 carbon atoms where observed, multiple signals overlapping at a range of 14.13-34.21ppm corresponding to the aliphatic CH3 (<b>C18</b>), CH2 (<b>C2, C3, C4, C5, C6, C7, C15, C16, and C17</b>) and allylic (<b>C8, C14</b>) carbon atoms. Signals at 127.90-130.24ppm were assigned to the olefienic C atoms (<b>C9, C10, C12</b>, and <b>C13</b>) while signal of 172.87ppm and 173.32ppm were assigned to the carbonyl (<b>C</b>=O) carbon atoms (<b>C1 </b>and<b> C2</b>) respectively (Table 2). </p> <p>Analysis with DEPT-135, H-H COSY, HMBC and HSQC assignments of CA1 augments assignment of signals made for CA1 from <sup>1</sup>H-NMR and <sup>13</sup>C-NMR and corresponded to that of Trilinolein <u>(<a href="https://pubchem.ncbi.nlm.nih.gov/#query=C57H98O6">C<sub>57</sub>H<sub>98</sub>O<sub>6</sub></a>, </u>MW 879.4 g/mol). The isolated compound was positive for the acrolein test for triglycerides; fat & oil and had an IC<sub>50</sub> of 46.08µg/ml radical scavenging activity.</p>

scholarly journals Reactions of 3-(p-substituted-phenyl)-5-chloromethyl-1,2,4-oxadiazoles with KCN leading to acetonitriles and alkanes via a non-reductive decyanation pathway

2018 ◽  
Vol 14 ◽  
pp. 3011-3017
Author(s):  
Akın Sağırlı ◽  
Yaşar Dürüst
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Synthetic Route ◽  
X Ray ◽  
H Nmr ◽  
2D Nmr Spectra ◽  
Tof Ms ◽  
C Nmr

The present work describes an unfamiliar reaction of 5-(chloromethyl)-3-substituted-phenyl-1,2,4-oxadiazoles with KCN affording trisubstituted 1,2,4-oxadiazol-5-ylacetonitriles and their parent alkanes, namely, 1,2,3-trisubstituted-1,2,4-oxadiazol-5-ylpropanes. To the best of our knowledge, the current synthetic route leading to decyanated products will be the first in terms of a decyanation process which allows the transformation of trisubstituted acetonitriles into alkanes by the incorporation of KCN with the association of in situ-formed HCN and most likely through the extrusion of cyanogen which could not be detected or isolated. In addition, the plausible mechanisms were proposed for both transformations. The structures of the title compounds were identified by means of IR, 1H NMR, 13C NMR, 2D NMR spectra, TOF–MS and X-ray measurements.

scholarly journals The NMR Spin Systems of Scutellaria 8β,13-Epoxy-neo-clerod-3-en-15,16-olides and Revision of 1H and 13C NMR Spectra Reported Data

2020 ◽  
Vol 15 (10) ◽  
pp. 1934578X2093378
Author(s):  
Josep Coll Toledano
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Spin Systems ◽  
13C Nmr Spectra ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
Reported Data ◽  
New Compounds ◽  
C Nmr ◽  
Shielding Effects

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.

scholarly journals New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

2007 ◽  
Vol 62 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Stephan W. Kohl ◽  
Katharina Kuse ◽  
Markus Hummert ◽  
Herbert Schumann ◽  
Clemens Mügge ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Ester ◽  
Nmr Spectra ◽  
Acid Ethyl Ester ◽  
Affinity Tags ◽  
X Ray ◽  
H Nmr ◽  
Synthetic Routes ◽  
New Compounds ◽  
C Nmr

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.

Direct observation of low spin – high spin electronic ground states and cross-over exchange in manganocene derivatives, (η5-C5H4R)2Mn, R = H, CH3, C2H5 by paramagnetic nuclear magnetic resonance

1986 ◽  
Vol 64 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Daniel Cozak ◽  
François Gauvin ◽  
Jacques Demers
Keyword(s):  
Nmr Spectra ◽  
Spin Exchange ◽  
Exchange Process ◽  
Paramagnetic Species ◽  
Temperature Range ◽  
H Nmr ◽  
Low Field ◽  
Spin Electronic ◽  
Electronic Ground ◽  
C Nmr

The paramagnetic 1H nmr spectra for manganocene (1) and 1.1′-dimethylmanganocene (2), and the 13C nmr spectra for 1,1′-diethylmanganocene (3) have been recorded in toluene solvent over a −90 to 90 °C temperature range. 1 shows a low field and a high field ring proton resonance in its spectrum near −59 °C. At higher temperatures the low field resonance is prevalent and becomes gradually averaged due to a fast spin exchange process that dominates the spectrum at 90 °C. For the ring substituted derivatives 2 and 3, resonances due to only one paramagnetic species were detected in the low temperature range. Above ambient temperature a new spectrum due to rapid spin exchange averaging is observed for these complexes. Results are readily interpreted in terms of ground state molecular cross-over exchanges between the 2E2g, 6A1g, and 2A1g spin states of the complexes.

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