Showing papers by "G. I. Nikishin published in 1976"
TL;DR: In this article, the stereoisomeric composition of the oxidation products does not depend on concentration of initial olefin, and a mechanism was proposed for the process, including intermediate formation of the ion-radical salt.
Abstract: 1.
Oxidation of cis- and trans-stilbene with Mn(III) and Co(III) acetates and Tl(III) trifluoroacetate yielded the corresponding acetates and trifluoroacetates of isomeric hydrobenzoins (meso- and dl-).
2.
The stereoisomeric composition of the oxidation products does not depend on concentration of initial olefin.
3.
A mechanism was proposed for the process, including intermediate formation of the ion-radical salt:\([stilbene]^{\mathop \cdot \limits^ + } [MX_3 ]^{\mathop \cdot \limits^ - } \).
2 citations
TL;DR: In this article, a new method was proposed for the synthesis of γ-alkyl-Δα,β-butenolides by oxidative dehydrocarboxylation ofγ -alkylparaconic acids by the S2O82−-AgNO3-CuSO4 system.
Abstract: A new method is proposed for the synthesis of γ-alkyl-Δα,β-butenolides by oxidative dehydrocarboxylation ofγ -alkylparaconic acids by the S2O8
2−-AgNO3-CuSO4 system.
1 citations
TL;DR: The radical chain process for the formation of γ-lactones from alcohols and β-alkyl-substituted α, β-unsaturated acids is accelerated substantially with increase in the pressure.
Abstract: 1
The radical-chain process for the formation of γ-lactones from alcohols andβ-alkyl-substitutedα, β-unsaturated acids is accelerated substantially with increase in the pressure
2
Sterically hindered reactions, which practically do not go under ordinary conditions, can be run at a pressure of 10,000 kgf/cm2 to give γ-lactones in a preparative yield
1 citations
TL;DR: In this article, 2-Carboxyethyl radicals add to the C=O group of aldehydes, with the formation of alkoxyl adduct-radicals that cleave H atoms from the aldehyde and are converted toγ-lactones.
Abstract: 1.
2-Carboxyethyl radicals add to the C=O group of aldehydes, with the formation of alkoxyl adduct-radicals that cleave H atoms from the aldehyde and are converted toγ-lactones.
2.
2-Carbomethoxyethyl radicals add to the C=O group of biacetyl and ethyl pyruvate, and the obtained adduct-radicals decompose to give methyl levulinate.
TL;DR: When 2-methyl-2-peroxytetrahydrofuran is reduced with FeCl2, or with the FeSO4-FeCl3 system, the generated 3-acetoxypropyl radicals are oxidized to 3acetoxy propyl chloride as discussed by the authors.
Abstract: 1.
2-Methyl-2-peroxytetrahydrofuran under the influence of FeSO4 or the FeSO4-CuSO4 system decomposes to give 3-acetoxypropyl radicals, which predominantly recombine to 1,6-hexanediol diacetate.
2.
When 2-methyl-2-peroxytetrahydrofuran is reduced with FeCl2, or with the FeSO4-FeCl3 system, the generated 3-acetoxypropyl radicals are oxidized to 3-acetoxypropyl chloride.
TL;DR: In this article, the relationship between the ability of these radicals to undergo oxidative cyclization to lactones and the number of methylene groups (n) and also the effect of copper ions on the oxidative cyclization process was investigated.
Abstract: 1.
ω-Carboxyalkyl radicals HOOC(CH2)nCH2, where n=4–7, were generated by the oxidative decarboxylation of pentane-, hexane-, heptane-, and octanedicarboxylic acids at 60°C in aqueous solution by the action of Na2S2O8 in the presence of silver nitrate. The relation between the ability of these radicals to undergo oxidative cyclization to lactones and the number of methylene groups (n) and also the effect of copper ions on the oxidative cyclization process were investigated.
2.
The main products from oxidative cyclization ofω-carboxyalkyl radicals in the absence of copper ions areγ-alkyl-γ-butyrolactones. In addition, alkanoic acids (84–95%) are formed as a result of abstraction of H atoms from the organic substrates by the radicals.
3.
The main products from the oxidative cyclization of theω-carboxyalkyl radicals in the presence of copper ions areγ-alkyl-Δα,β-butenoiides.ω-Alkenoic acids (58–98%) are formed as a result of the oxidativeβ-deprotonation of the radicals by the action of Cu(II).
TL;DR: The reaction of succinic anhydride with C8−C18-alkenes, initiated by tert-butyl peroxide, leads to the formation of n-alkylsuccinic anoxide, the yield of which under the optimum conditions is 50-75% as discussed by the authors.
Abstract: The reaction of succinic anhydride with C8−C18-alkenes, initiated by tert-butyl peroxide, leads to the formation of n-alkylsuccinic anhydrides, the yield of which under the optimum conditions is 50–75%.