Stereochemistry of some substituted 2-furyl- and 2-thienyl ethylene derivatives. 1H NMR study

1982 ◽  
Vol 47 (12) ◽  
pp. 3412-3417 ◽  
Author(s):  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Daniel Végh ◽  
Vladimír Žvak
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Side Chain ◽  
H Nmr ◽  
Nmr Study ◽  
Thiophene Derivatives

Stereochemistry of (E)- and (Z)-1-(5-nitro-2-furyl)-2-Y-ethylenes and 1-(5-nitro-2-thienyl)-2-Y-ethylenes (where Y = CH3O, 4-CH3C6H4O, N3 and Br) and of E and Z isomers of methyl 2-methyl-3-(2-furyl)propenoate and methyl 2-methyl-3-(2-thienyl)propenoate was studied by 1H NMR spectroscopy. With 1-(5-nitro-2-furyl)-2-Y-ethylenes, it was found that the preferred conformation of the furyl substituent relative to the side chain double bond is s-trans in the E isomers and s-cis in the Z isomers. The s-cis conformation is prevailing in both isomers of methyl 2-methyl-3-(2-furyl)propenoate. The E and Z isomers of all studied thiophene derivatives exist in the s-trans conformation.

1H and 13C NMR study of some substituted 2-furyl- and 2-thienylethylene derivatives

1986 ◽  
Vol 51 (4) ◽  
pp. 889-898 ◽  
Author(s):  
Miloslava Dandárová ◽  
Daniel Végh ◽  
Jaroslav Kováč ◽  
Igor Goljer ◽  
Nadežda Prónayová ◽  
...  
Keyword(s):  
Double Bond ◽  
Heterocyclic Ring ◽  
Coupling Constants ◽  
Side Chain ◽  
1H And 13C Nmr ◽  
H Nmr ◽  
Nmr Data ◽  
Nmr Study ◽  
Thiophene Derivatives ◽  
C Nmr

The 1H and 13C NMR spectral data of 1-(5-nitro-2-furyl)-2-X-2-Y-ethylenes and some their thienyl analogues are presented. Geometrical arrangement of the trisubstituted ethylenes was adduced from vicinal coupling constants 3J(C, H) for the carbon atom at the functional group attached to the double bond and the ethylene proton. The orientation of the heterocyclic ring towards the double bond of the side chain was determined from the 1H NMR data. The preferred s-cis or s-trans conformations of 5-nitro-2-furylethylene derivatives is substituent at the double bond dependent; all thiophene derivatives under study were found in the s-trans conformation.

Steroids with the β-crotonate (2-butenoate) side chain

1986 ◽  
Vol 51 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Ivan Černý ◽  
Vladimír Pouzar ◽  
Pavel Drašar ◽  
František Tureček ◽  
Miroslav Havel
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
Lithium Salt ◽  
Side Chain ◽  
H Nmr ◽  
C Nmr

Ethyl (20E)-3β-methoxymethoxy-24-nor-5,20(22)-choladien-23-oate (Va) and analogous derivatives with 5α,5β and Δ5,14 steroid moiety (Vb,Vc and Vd, respectively) were prepared by Wittig-Horner reaction of the corresponding ketones IIa-IId with diethyl ethoxycarbonylmethylphosphonate. In this case the reaction affords exclusively the (E)-isomers, in contrast with the Peterson reaction with lithium salt of ethyl 2-(trimethylsilyl)acetate which gives a mixture of (E)- and (Z)-isomers at the Δ20(22) double bond. The structure of the products was confirmed by 1H NMR and 13C NMR spectroscopy. The crotonates Va-Vd were further converted into the 3-O-succinyl derivatives VIIIa-VIIId.

29Si, 13C and 1H NMR spectra of some trimethylsiloxy- and bis(trimethylsiloxy)butene isomers

1983 ◽  
Vol 48 (11) ◽  
pp. 3097-3103 ◽  
Author(s):  
Jan Schraml ◽  
Ján Šraga ◽  
Pavel Hrnčiar
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
Oxygen Atom ◽  
1H Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
1H Nmr Spectra ◽  
Trimethylsilyl Group ◽  
H Nmr ◽  
Steric Crowding

Three isomers of trimethylsiloxybutene were prepared and identified by 1H NMR spectroscopy to be 2-trimethylsiloxy-1-butene and E and Z 2-trimethylsiloxy-2-butenes. E and Z isomers of 2,3-bis(trimethylsiloxy-2-butene were also prepared. 29Si and 13C chemical shifts in these compounds are interpreted. The shifts indicate that the spatial arrangements in the CH3-C-O-Si(CH3)3 fragment is the same in all the pertinent compounds. Steric crowding forces the trimethylsilyl group to assume conformations in which conjugation between unshared electrons of oxygen atom and the electrons of the double bond is inhibited. As a result, olefinic β carbons are deshielded and the shielding of the silicon is increased.

scholarly journals 1H NMR Study of the Enantioselective Binding ofΛ- andΔ-[Ru(bpy)2(m-bpy-GHK)]Cl2to the Deoxynucleotide Duplex d(5'-C1G2C3G4A5A6T7T8C9G10C11G12-3')2

2005 ◽  
Vol 3 (1-2) ◽  
pp. 109-117 ◽  
Author(s):  
A. Myari ◽  
N. Hadjiliadis ◽  
A. Garoufis
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Minor Groove ◽  
Major Groove ◽  
Nmr Analysis ◽  
Groove Binding ◽  
H Nmr ◽  
Nmr Study ◽  
Oligonucleotide Duplex ◽  
Diastereomeric Complexes

The interaction of the diastereomeric complexes Λ- andΔ-[Ru(bpy)2(m-GHK)]Cl2, (GHK = glycine-histidine-lysine) to the deoxynucleotide duplex d(5'-CGCGAATTCGCG-3')2was studied by means of1H NMR spectroscopy. The diastereomers interact with the oligonucleotide duplex differently. TheΔ-[Ru(bpy)2(m-GHK)]Cl2is characterized by major groove binding close to the central part of the oligonucleotide, with both the peptide and the bipyridine ligand of the complex involved in the binding. TheΛ-[Ru(bpy)2(m-bpy-GHK)]Cl2binds loosely, approaching the helix from the minor groove. The NMR analysis shows that the peptide (GHK) binding has a determinative role in the interactions of both diastereomers with the oligonucleotide.

1H NMR Study of the Reaction of Diacetylmelamine with Oxiranes

1997 ◽  
Vol 51 (3) ◽  
pp. 438-442 ◽  
Author(s):  
Jacek Lubczak
Keyword(s):  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
1H Nmr ◽  
Molar Ratio ◽  
Intramolecular Rearrangement ◽  
H Nmr ◽  
Nmr Study

The reaction of 1 mole of melamine with 2 moles of acetic anhydride leads to diacetylmelamine (DAM), which is a mixture of two constitutional isomers: 90% N, N′-DAM and 10% N,N-DAM The reaction of 1 mole of DAM with 1–8 moles of oxiranes (ethylene and propylene oxides) was studied by 1H NMR spectroscopy. At the molar ratio of substrates 1: ∼ 2, no N,N′-diacetyl- N,N′-bis(2-hydroxyalkyl)melamine was formed, but the product of its intramolecular rearrangement, N,N′-bis(2-acetyloxyalkyl)melamine, was found. The latter reacted with the excess of oxiranes to appropriate tetrafunctional polyetherols containing s-triazine rings.

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

A 15N, 13C, and 1H NMR study of reaction products from arylguanidines and chloroformate esters

1991 ◽  
Vol 56 (7) ◽  
pp. 1505-1511 ◽  
Author(s):  
Antonín Lyčka ◽  
Karel Palát
Keyword(s):  
1H Nmr ◽  
Nmr Spectra ◽  
Reaction Products ◽  
H Nmr ◽  
Nmr Study

The 15N, 13C, and 1H NMR spectra of the reaction products from arylguanidines with two mols of chloroformate esters have been measured. With application of the corresponding 15N isotopomer it has been proved that the reaction products have the structures IIIa-IIIc.

Different submicellar solubilization mechanisms revealed by 1H NMR and 2D diffusion ordered spectroscopy (DOSY)

2020 ◽  
Vol 22 (19) ◽  
pp. 11075-11085
Author(s):  
Mengjian Wu ◽  
Zhaoxia Wu ◽  
Shangwu Ding ◽  
Zhong Chen ◽  
Xiaohong Cui
Keyword(s):  
Nmr Spectroscopy ◽  
Sodium Dodecyl Sulfate ◽  
1H Nmr ◽  
Sodium Dodecyl ◽  
Butyl Methacrylate ◽  
H Nmr ◽  
Molecular Scale ◽  
Two Systems ◽  
Dodecyl Sulfate ◽  
Triton X

Different submicellar solubilization mechanisms of two systems, Triton X-100/tetradecane and sodium dodecyl sulfate (SDS)/butyl methacrylate, are revealed on the molecular scale by 1H NMR spectroscopy and 2D diffusion ordered spectroscopy (DOSY).

scholarly journals Tautomerisation in 1-(4-Methylphenylazo)naphthalen-2-ol and 2-(4-Methylphenylazo)-4-methylphenol: A Crystallographic and 13C{1H}NMR Study

1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Resonant Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Nmr Study ◽  
Acetic Acid Esters ◽  
Acid Esters ◽  
Equivalent Carbon

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.

scholarly journals Assessment of 1H NMR Spectroscopy for Specific Metabolite Fingerprinting of Angelica sinensis

2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Dongmin Su ◽  
Jinglan Han ◽  
Shishan Yu ◽  
Hailin Qin
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Authentic Sample ◽  
Angelica Sinensis ◽  
Metabolite Fingerprinting ◽  
H Nmr ◽  
Pure Compounds ◽  
Polar Extracts

The 1H NMR fingerprints of fractionated non-polar extracts (CSPD A) from the roots of Angelica sinensis of six different specimens were assigned by comparison with the 1H NMR spectra of the isolated pure compounds. The 1H NMR fingerprints showed exclusively characteristic resonance signals of the major constituents of the plant. The 1H NMR fingerprint established for an authentic sample of A. sinensis can be used for authenticating A. sinensis species.

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