Oxidation and epoxidation of 4,4-dimethyl-A-homo-5-cholesten-4a-ols

1985 ◽  
Vol 50 (1) ◽  
pp. 114-131 ◽  
Author(s):  
Helena Velgová ◽  
Jaroslav Zajíček
Keyword(s):  
Double Bond ◽  
Membered Ring ◽  
Allylic Alcohols ◽  
Cyclic System ◽  
H Nmr ◽  
Nmr Data ◽  
Epoxidation Of Olefins

Oxidation of four stereoisomeric 3-acetoxy-4,4-dimethyl-A-homo-5-cholesten-4a-ols I-IV with Sarett's and Jones's reagent was investigated. 4αβ-Hydroxy derivatives II and IV afforded corresponding enones V and XVI as the main products, while in the case of 4aα-hydroxy derivatives I and III the formation of 5β,6β-epoxides was observed both in the oxidation according to Jones and in the oxidation with the Sarett's reagent. The study of the stereochemistry of epoxidation of olefins I-IV and their derivatives showed that the epoxidation of the 5,6-double bond takes place preferentially from the β-side of the cyclic system. On the basis of 1H NMR data the preferred conformation of the seven-membered ring A in the allylic alcohols I-IV was determined; on its basis the effects leading to different behaviour of epimers I, III and II, IV during oxidation are discussed.

Analysis of 1H-NMR spectra of cinnamaldehyde type model substances of lignin

1980 ◽  
Vol 45 (2) ◽  
pp. 330-334 ◽  
Author(s):  
Tibor Liptaj ◽  
Milan Remko ◽  
Ján Polčin
Keyword(s):  
Double Bond ◽  
Nmr Spectra ◽  
Side Chain ◽  
Type Model ◽  
Stable Conformer ◽  
Spectra Analysis ◽  
H Nmr ◽  
Nmr Data ◽  
Lignin Model ◽  
Model Substances

1H-NMR spectra of the following lignin model substances have been analyzed: cinnamaldehyde, 2-methoxycinnamaldehyde, 3-methoxycinnamaldehyde, 4-methoxycinnamaldehyde, 3,4-dimethoxycinnamaldehyde, 3-methoxy-4-hydroxycinnamaldehyde and 3,4,5-trimethoxycinnamaldehyde. From the NMR spectra analysis it follows that the studied compounds exist in solutions as trans isomers. Theoretical (PCILO) calculations in agreement with the NMR data have shown that the more stable conformer has trans orientation of C=O group with respect to the double bond of the conjugated side chain.

A contribution to peroxy acid oxidation of α,β-unsaturated ketones and linearly conjugated dienones: Reactions in the cholestane series

1988 ◽  
Vol 53 (7) ◽  
pp. 1549-1567 ◽  
Author(s):  
Václav Černý ◽  
Miloš Buděšínský ◽  
Miloš Ryba ◽  
František Tureček
Keyword(s):  
Double Bond ◽  
Carbonyl Group ◽  
Acid Oxidation ◽  
Peroxy Acid ◽  
Unsaturated Ketones ◽  
H Nmr ◽  
Nmr Data ◽  
Epoxy Ketones ◽  
C Nmr

Oxidation with 3-chloroperoxybenzoic acid of s-cis α,β-unsaturated ketones IX, XI and s-trans types X, XII was compared. The s-cis ketones show higher reactivity and furnish a higher yield of the corresponding α,β-epoxy ketones than the s-trans ketones. Products of the Baeyer-Villiger reaction are formed only in low yield. The dienone VI is oxidized predominantly to VII thus violating the rule that linear conjugated dienones are epoxidized at the double bond more distant from the carbonyl group; this result is in accord with the behaviour of s-cis α,β-unsaturated ketones. 1H NMR and 13C NMR data of the starting compounds and of the products are reported.

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.

scholarly journals Synthesis of Regio- and Stereospecifically Deuterium Labelled 2-Benzylindanes

1984 ◽  
Vol 39 (3) ◽  
pp. 369-374 ◽  
Author(s):  
Dietmar Kuck
Keyword(s):  
Double Bond ◽  
High Selectivity ◽  
Membered Ring ◽  
Deuterium Incorporation ◽  
Deuterium Labelling ◽  
H Nmr

2-Benzylindenes (1, 1a ) are hydrogenated to 2-benzylindanes (2) using tris-(triphenylphosphine)- rhodium (I)-chloride in benzene by a strict cis-1,2 addition of hydrogen to the double bond. Thus, stereo- and regio-specific deuterium labelling at the five-membered ring of various 2-benzylindanes has been carried out. The high selectivity of deuterium incorporation is shown independently by 1H NMR and mass (MIKE*) spectrometry of selected 2-benzylindanes.

15N, 13C, and 1H NMR Spectra of Azo and Hydrazo Compounds Derived from 1,3,3-Trimethyl-2-methylidene-2,3-dihydroindole (Fischer Base)

1998 ◽  
Vol 63 (7) ◽  
pp. 1012-1020 ◽  
Author(s):  
Antonín Lyčka ◽  
Josef Jirman ◽  
Alois Koloničný
Keyword(s):  
Double Bond ◽  
Hydrochloric Acid ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Azo Compounds ◽  
Passive Component ◽  
Geometric Isomers ◽  
H Nmr ◽  
Fischer Base ◽  
Hydrazone Form

The 15N, 13C, and 1H NMR spectra were measured for azo and hydrazo compounds derived from 1,3,3-trimethyl-2-methylidene-2,3-dihydroindole (Fischer base), which is a passive component with a terminal methylidene group. Products prepared by coupling in hydrochloric acid exist in the corresponding hydrazone form as the E-isomers. Neutralization gives a mixture of two isomeric azo compounds which differ in the arrangement at the C(2)=C(10) double bond. This mixture was alkylated with methyl iodide to obtain the =N-N(CH3)- hydrazone derivatives. The geometric isomers were resolved based on the NOESY approach and the stereospecific behaviour of the 2J(15N,13C) coupling constants was studied for the 15N-labelled compounds.

scholarly journals Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 65
Author(s):  
Byeoung-Kyu Choi ◽  
Duk-Yeon Cho ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
Hee Jae Shin
Keyword(s):  
Nitric Oxide ◽  
Mass Spectrometry ◽  
Optical Rotation ◽  
Chemical Oxidation ◽  
Culture Broth ◽  
Membered Ring ◽  
Microglial Cells ◽  
No Production ◽  
Nmr Data ◽  
Ic50 Value

Two new phomaligols, deketo-phomaligol A (1) and phomaligol E (2), together with six known compounds (3–8) were isolated from the culture broth of the marine-derived fungus Aspergillus flocculosus. Compound 1 was first isolated as a phomaligol derivative possessing a five-membered ring. The structures and absolute configurations of the new phomaligols were determined by detailed analyses of mass spectrometry (MS), nuclear magnetic resonance (NMR) data, optical rotation values and electronic circular dichroism (ECD). In addition, the absolute configurations of the known compounds 3 and 4 were confirmed by chemical oxidation and comparison of optical rotation values. Isolated compounds at a concentration of 100 μM were screened for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among the compounds, 4 showed moderate anti-neuroinflammatory effects with an IC50 value of 56.6 μM by suppressing the production of pro-inflammatory mediators in activated microglial cells without cytotoxicity.

Inhibited rotation of amide group around C N bond of nicotinamide in different solvents by 1 H NMR data

2017 ◽  
Vol 231 ◽  
pp. 238-241 ◽  
Author(s):  
G.A. Gamov ◽  
V.V. Aleksandriiskii ◽  
V.A. Sharnin
Keyword(s):  
Amide Group ◽  
H Nmr ◽  
Nmr Data

Chemie polyfunktioneller Moleküle, 108 Tetraedrische Kupfer(I)-Chelatkomplexe der Liganden Bis(diphenylphosphino)amin und Bis(diphenylphosphino)methan / Chemistry of Polyfunctional Molecules, 108 [1] Tetrahedral Copper(I) Chelate Complexes with the Ligands Bis(diphenylphosphino)amine and Bis(diphenylphosphino)methane

1991 ◽  
Vol 46 (12) ◽  
pp. 1699-1705 ◽  
Author(s):  
Jochen Ellermann ◽  
Falk A. Knoch ◽  
Klaus J. Meier
Keyword(s):  
Membered Ring ◽  
Monoclinic Space Group ◽  
Direct Reaction ◽  
Conductivity Data ◽  
Chelate Complexes ◽  
X Ray ◽  
Lattice Constants ◽  
H Nmr ◽  
Highly Strained ◽  
Nitrate Anions

Reaction of [Cu(PPh3)2(NO3)] (1) in acetone with bis(diphenylphosphino)amine (dppa, 2) yields [Cu(dppa)(PPh3)2]+NO3- (3a). [Cu(dppa)(PPh3)2]+PF6- (3b) has been synthesized by metatheses of 3a with NH4PF6. The salt [Cu(dppm)(PPh3)2]+PF6- (5b) has been prepared by an one batch reaction of [Cu(PPh3)2(NO3)] (1), bis(diphenylphosphino)methane (dppm, 4) and NH4PF6 in methanol, because [Cu(dppm)(PPh3)2]+NO3- (5a) could not be isolated by the direct reaction of 1 with 4. The IR, Raman, 31P{1H} NMR, 1H{31Ρ} NMR as well as the conductivity data are reported and discussed together with the X-ray crystal structure of 3a · 1.8 (CH3)2CO. The structure consists of copper atoms coordinated tetrahedrally by two PPh3 ligands and the chelating dppa ligand and features a highly strained four-membered ring. The distorted tetrahedral cations are hydrogen bridged to the nitrate anions. The colourless needles of 3a· 1.8 (CH3)2CO crystallize in the monoclinic space group C 2/c, with the lattice constants a = 4189.2(27); b = 1223.7(8); c = 2717.8(15) pm;β = 113.16(4)°.

scholarly journals STUDY OF CONFORMATIONAL PREFERENCES OF ERYTHRO-CAROLIGNAN E ASSESSED BY THE COUPLING BETWEEN H7'-H8' IN DIFFERENT NMR SOLVENTS

2016 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Rudiyansyah Rudiyansyah ◽  
Ajuk Sapar ◽  
Masriani Masriani
Keyword(s):  
Ethanol Extract ◽  
Coupling Constant ◽  
Relative Configuration ◽  
H Nmr ◽  
Nmr Data ◽  
Conformational Preferences ◽  
Wood Bark

<p><em>Erythro</em>-carolignan E (<strong>1</strong>) has been obtained from the ethanol extract of the wood bark of <em>Durio affinis</em> Becc. This research was conducted in order to prove that conformational preferences of compound <strong>1</strong> were solvent dependent. On the basis of <sup>1</sup>H-NMR data, the relative configuration of compound <strong>1</strong> was characterized by a coupling constant (<sup>3</sup><em>J</em><sub>HH</sub>) value of 3.3 Hz at H-7' in CDCl<sub>3</sub>. The coupling constant (<sup>3</sup><em>J</em><sub>HH</sub>) values of H-7' in compound <strong>1</strong> has changed to 4.1 Hz and 5.3 Hz in pyridine-<em>d</em><sub>5</sub> and acetonitrile-<em>d</em><sub>3</sub> respectively. As a result, the conformation of compound <strong>1</strong> at C7'-C8' has changed in different NMR solvents.  In conclusion, structure of<em>erythro</em>-carolignan E that contains a dihydroxy group at C7'-C8' is able to change in different NMR solvent.</p>

scholarly journals Synthesis of Some Novel Fused Imidazo [2, 1-b] [1, 3] Thiazole and Imidazo [2, 1-b] Thiazolo [5, 4-d] Isoxazole Derivatives

2012 ◽  
Vol 9 (3) ◽  
pp. 1518-1525 ◽  
Author(s):  
Hamid Reza Jaberi ◽  
Hadi Noorizadeh
Keyword(s):  
Acetic Acid ◽  
Sodium Acetate ◽  
Carbon Disulphide ◽  
Thiazole Derivatives ◽  
H Nmr ◽  
Nmr Data ◽  
Elemental Analyses ◽  
New Compounds ◽  
Isoxazole Derivatives ◽  
C Nmr

In this work we describe the synthesis of some novel fused imidazo [2, 1-b] [1, 3] thiazole derivatives. The reaction of 1, 2-diaminoethane 1 with carbon disulphide in H2O/ETOH as solvent furnishes 4, 5-dihydro-1H-imidazol-2-thiol 2 under reflux condition. the reaction of 4,5-dihydro-1H-imidazol-2-thiol on treatment with ethylchloro acetate and aromatic aldehyde in presence of anhydrous sodium acetate and acetic acid as solvent to give (Z)-2-(arylidene)-5,6-dihydroimidazo [2,1-b] [1,3] thiazol-3(2H)-one 3a-j. Compounds 3a-j was condensed with hydroxylamine to give 3-(aryl)-2, 3, 6, 7-tetrahydroimidazo [2, 1-b] [1,3] thiazolo [5, 4-d] isoxazole 4a-j. The structures of the new compounds were established by elemental analyses, IR,1H NMR and13C NMR data.

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