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.

Sulphonated Poly(ethylene terephthalate)/Poly(3-hydroxy butyrate) Blends: Miscibility, Thermal Behavior, and Specific Interactions

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Rafael Silva ◽  
Gizilene M. Carvalho ◽  
Edvani C. Muniz ◽  
Gentil J. Vidotti ◽  
Adley F. Rubira
Keyword(s):  
Carbonyl Group ◽  
Specific Interaction ◽  
Thermal Stabilities ◽  
Immiscible Blends ◽  
H Nmr ◽  
Miscible Blends ◽  
Poly Ethylene Terephthalate ◽  
Concentration Changes ◽  
Poly Ethylene ◽  
C Nmr

AbstractPETs/PHB blends with different compositions were produced by “casting” method. The blends were investigated by TGA, DSC, 1H and 13C NMR and FTIR. Phase separation occurred during blend preparation. PETs and PHB were present in both formed phases. The phases presented different thermal stabilities unrelated to phase component concentration changes. The miscibility study by DSC showed that PHB-phase rich blends are immiscible, whereas the PETs-rich phase blends are miscible. The 1H NMR spectra of the miscible blends exhibited a peak close to the PHB methylene signal, which is in accordance with the interaction between the PETs SO3 - groups and the PHB carbonyl groups. This interaction result in a shift of the PHB carbonyl group absorption band in the FTIR spectra and a variation in the chemical shift of the PHB carbonyl group resonance peak in solid state 13C NMR. No specific interaction was observed for the immiscible blends.

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.

Anwendungen der 2 D-NMR-Spektroskopie in der Organophosphorchemie Beispiel: L-Menthyldichlorphosphan / Applications of the 2D NMR Spectroscopy in the Organophosphorus Chemistry Example: L-Menthyldichlorophosphine

1982 ◽  
Vol 37 (12) ◽  
pp. 1661-1664 ◽  
Author(s):  
Martin Feigel ◽  
Gerhard Hägele ◽  
Axel Hinke ◽  
Gudrun Tossing
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
H Nmr ◽  
Nmr Parameters ◽  
Nmr Data ◽  
Organophosphorus Chemistry ◽  
C Nmr

2D NMR ist used to determine the 1H NMR parameters of L-Menthyldichlorophosphine. 13C NMR data are given

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.

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.

Übergangsmetall-Carbin-Komplexe, XC. Synthese neuer, siebenfach-koordinierter, kationischer Carbin-Komplexe des Wolframs in einer höheren Oxidationszahl / Transition Metal Carbyne Complexes, XC. Synthesis of New, Seven Coordinated, Cationic Tungsten Carbyne Complexes in a Higher Oxidation State

1988 ◽  
Vol 43 (6) ◽  
pp. 654-657 ◽  
Author(s):  
Alexander Constantin Filippou ◽  
Ernst Otto Fischer ◽  
Helmut Guido
Keyword(s):  
Electrical Conductivity ◽  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Carbonyl Group ◽  
Oxidation State ◽  
Ionic Character ◽  
H Nmr ◽  
Elemental Analyses ◽  
Carbyne Complexes ◽  
C Nmr

The reaction of (I)3(CO)L2W≡CNEt2 (L2 = 2.2'-bipyridyl(2.2'-bipy); 1.10-phenanthroline (ophen)) (1, 2) with two equivalents of tert-butylisonitrile results in the elimination of the carbonyl group and the displacement of one iodine ligand from the coordination sphere, leading to the new, cationic carbyne complexes [(I)2(t-C4H9NC)2L2W≡CNEt2]+I- (3, 4). The ionic character and composition of 3 and 4 was confirmed by the electrical conductivity of their solutions as well as by elemental analyses, IR, 1H NMR and 13C NMR spectroscopy.

scholarly journals A semisynthesis of 3'-O-ethyl-5,6-dihydrospinosyn J based on the spinosyn A aglycone

2017 ◽  
Vol 13 ◽  
pp. 2603-2609 ◽  
Author(s):  
Kai Zhang ◽  
Shenglan Liu ◽  
Anjun Liu ◽  
Hongxin Chai ◽  
Jiarong Li ◽  
...  
Keyword(s):  
Double Bond ◽  
Chemical Synthesis ◽  
Minor Component ◽  
Food Storage ◽  
Selective Protection ◽  
H Nmr ◽  
High Yields ◽  
Agriculture And Food ◽  
Hydrolysis Of ◽  
C Nmr

Spinetoram, a mixture of 3'-O-ethyl-5,6-dihydrospinosyn J (XDE-175-J, major component) and 3'-O-ethylspinosyn L (XDE-175-L, minor component), is a novel kind of green and efficient insecticide with a broad range of action against various insects. Nowadays, spinetoram is widely used in agriculture and food storage. This work reports a 7-step semisynthesis of 3'-O-ethyl-5,6-dihydrospinosyn J from spinosyn A aglycone. The C9–OH and C17–OH of the aglycone are successively connected to 3-O-ethyl-2,4-di-O-methylrhamnose and D-forosamine after selective protection and deprotection steps. Then, with 10% Pd/C as catalyst, the 5,6-double bond of the macrolide was selectively reduced to afford 3'-O-ethyl-5,6-dihydrospinosyn J. In addition, the 3-O-ethyl-2,4-di-O-methylrhamnose is synthesized from rhamnose which is available commercially, while the D-forosamine and aglycone are obtained via the hydrolysis of spinosyn A. High yields were obtained in each step, and all intermediates in the synthesis were characterized by 1H NMR, 13C NMR and MS techniques. This study can be helpful for developing an efficient chemical synthesis of spinetoram, and it also offers opportunities to synthesize spinosyn analogues and rhamnose derivatives.

Epoxide of a ketene acetal. The first 2,2-dialkoxyoxirane to be isolated

2001 ◽  
Vol 79 (2) ◽  
pp. 110-113 ◽  
Author(s):  
Malgorzata Dawid ◽  
Paul C Venneri ◽  
John Warkentin
Keyword(s):  
Ir Spectroscopy ◽  
Carbonyl Group ◽  
Ring Closure ◽  
Nucleophilic Attack ◽  
Carbonyl Carbon ◽  
Subsequent Formation ◽  
H Nmr ◽  
Carbonyl Ylide ◽  
Ketene Acetal ◽  
C Nmr

Dimethoxycarbene, generated at 110°C in benzene by thermolysis of 2,2-dimethoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline, reacted with cyclohexanone to afford 2,2-dimethoxyspiro[2.5]-1-oxaoctane. It is the first oxirane of a ketene acetal that could be isolated and characterized by 1H NMR-, 13C NMR-, and IR spectroscopy. The identical oxirane might be expected from conrotatory cyclization of the appropriate carbonyl ylide. That ylide was generated under identical conditions by thermolysis of an oxadiazoline precursor (3,4-diaza-2,2-dimethoxy-1-oxaspiro[4.5]dec-3-ene) (14). The ylide could either cyclize or fragment to dimethoxycarbene and cyclohexanone. Addition of 4-tert-butylcyclohexanone, to trap dimethoxycarbene in competition with the cyclohexanone generated from 14 and, to leave the ylide closure pathway as the only route to the oxirane, showed that the carbonyl ylide does cyclize. However, fragmentation of the carbonyl ylide is relatively fast compared to its cyclization and most of it fragments to dimethoxycarbene and cyclohexanone. Oxirane formation from the carbene and ketone is probably either a concerted cycloaddition or it occurs in two steps, by nucleophilic attack at the carbonyl carbon to form the C—C bond first, prior to ring closure. If the carbene is bonded first to O of the carbonyl group, as it is in the carbonyl ylide, subsequent formation of the C—C bond is too slow, relative to fragmentation of the ylide, to afford the oxirane ring efficiently.Key words: carbonyl ylide, dialkoxyoxirane, dimethoxycarbene, oxadiazoline, oxirane.

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