Permanganate oxidation effect

If a-phellandrene be oxidised by potassium permanganate, the principal body resulting is a-oxy-/3-isopropyl glutaric acid. If /3-phellandrene be oxidised, closely related acids result, but if a 1 per cent, solution of permanganate be used and the oxidation effected very carefully in the cold, with the terpene always in excess, a glycol, CjoHjg(OH)2, results, which when dehydrated with dilute sulphuric acid yields tetrahydro-cuminic aldehyde. 

In an earlier series of experiments, Cullis and Ladbury examined the kinetics of the permanganate oxidation of hydrocarbons in acetic acid solution. Initial attack on toluene occurs at the methyl group and a total order of two was found. Electron-withdrawing agents reduced the rate of oxidation. However, the effects of added salts were complex and the authors believe that lower oxidation states of manganese are responsible for the oxidation. The oxidation of ethylbenzene produced acetophenone, the process being second-order with... 

Rosenblatt etal have examined the effect of structure and isotopic substitution upon the permanganate oxidation of some alky famines (Table 4). The isotope effect of 1.84 is considered to be sufficiently low to be compatible with aminium radical-cation formation, and it is felt that, while C-H cleavage is significant for oxidation of primary amines, the dominant mode of oxidation of tertiary amines is electron-transfer, e.g. 

Fig. I. Isotope effect for acid permanganate oxidation of mandelic acid. Temperature = 26.2 °C [MnO -] = 1.4x10- M [H SO ] = 1.69 M.

The mechanisms of permanganate oxidations have been the subject of a fairly intensive study which has now lasted for almost a century. While many of these studies were carried out in aqueous solutions, much of what was learned is also germane to an understanding of the reactions which occur in phase transfer assisted reactions. Although most of these studies are interrelated they can conveniently be discussed under the following headings products, substituent effects, isotope effects, and solvent effects, with the latter being of particular importance to the phase transfer assisted reactions. 

Solvent Effects. Information on the effect of solvent polarity of the phase transfer assisted permanganate oxidation of alkenes has been obtained by studying the oxidation of methyl cinnamate by tetrabutylammonium permanganate in tv/o different solvents, acetone and methylene chloride (37). 

The pyrazine ring is stable toward permanganate oxidation, and this explains a variety of pyrazinecarboxylic acids that have been prepared from quinoxalines or benzo-fused quinoxalines. In contrast, alkyl side chains on pyrazines are effectively oxidized by permanganate, selenious acid, selenium dioxide, or dichromate to afford the corresponding carboxylic acids (Section 8.03.7.1). Oxidation of pyrazines with hydrogen peroxide or percarboxylic acids gives pyrazine A -oxides and/or A, A -dioxides (Section 8.03.5.2). 

In azide addition to quinones, the triazoline adducts are spontaneously oxidized to the triazoles.1-8 9,279-281,317,392 393 Potassium permanganate32,155,286,288 and nickel peroxide394 also effect triazoline oxidation. Permanganate oxidation of 1,5-substituted triazolines in a two-phase system using a phase-transfer catalyst provides a convenient route to the synthesis of 1,5-disubstituted triazoles (Scheme 118).395,396 Triazoline 4-carboxylic esters32,287,288 and a 4-carboxamide397 are converted to triazoles by potassium permanganate and nickel peroxide, respectively. 

Permanganate oxidation of alkenes. Substituent and solvent effects. Difficulties with MP2 calculations ... 

The oxidation of fluorinated derivatives, which requires chromium trioxide and hot, fuming nitric acid, usually stops at the mono-sulfone stage,although 2,2,4,4-tetrafluoro-l,3-dithietane is converted directly to the disulfone by treatment with chromium trioxide and boiling, fuming nitric acid. The conversion of 2,2,4,4-tetrachloro- or 2,2,4,4-tetrabromo-dithietane to the disulfone may be effected by oxidation to the monosulfone with potassium permanganate followed by treatment which chromium trioxide- nitric acid. Potassium permanganate oxidizes the dimer of thiocyclohexanone to the disulfone in 78% yield. 

This investigation was extended to wood and lignin chars prepared at 400 °C to determine the effect of preexisting aromatic nuclei of lignin in the charring reactions. The permanganate oxidation analysis indicated that these chars, like cellulose chars, have considerably condensed or cross-linked aromatic structures, even at 400 C. The NMR data also showed that the chars from similar cellulose, wood. 

Both C-13 ketones were presumably formed by further oxidation of the corresponding C-14 acids but attempts to convert the acid (X) to the ketone (XIV) by permanganate oxidation were unsuccessful the product of the reaction was the acid XVII. However, a conversion of acid XVII into ketone XVIII was effected by a more circuitous route ... 

Houk, K. N., Strassner, T. Establishing the (3 + 2) mechanism forthe permanganate oxidation of alkenes by theory and kinetic isotope effects. J. Org. Chem. 1999, 64, 800-802. 

Ring-breaking oxidation is effected with periodate, permanganate, nitric acid, or halogen (basic solution). Proio-quercitol shows anomalous uptake of periodate (8 moles/mole). The products of mild permanganate oxidation, such as deoxyhexaric acids, are useful for characterization. ... 

Incineration and molten metal treatment are effective ways to destroy this componnd. Potassium permanganate oxidation is a snit-able method of destruction in the laboratory. 

Potassium permanganate has an oxidizing effect on many organic and a number of inorganic substances under acidic, neutral and alkaline conditions. 

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