Potassium permanganate alkane oxidation

Trifluoroacetic acid is a useful medium for a number of oxidation reactions It IS highly resistant to strong oxidants, even to permanganates and chromates For instance, various alkanes, cycloalkanes, and arenes can be oxidized degradatively by potassium permanganate in trifluoroacetic acid under mild conditions [28]... 

Metallic oxidants, namely, chromic acid and potassium permanganate, may be used to oxidize alkanes to alcohols or ketones, but these reagents have only limited synthetic value. Alkaline KMnC>4 is rather ineffective, mainly because of the insolubility of alkanes in the aqueous solution of the reagent. Oxidations in acidic solutions such as aqueous CF3COOH,108 or the use of special reagents such as benzyltriethylammonium permanganate109 may give better results. 

Reaction with potassium permanganate. Dilute or alkaline solutions of KMn04 oxidize unsaturated compounds. Alkanes and aromatic compounds are generally unreactive. Evidence that a reaction has occurred is observed by the loss of the purple color of KMn04 and the formation of the brown precipitate manganese dioxide, Mn02. 

Solution It is known that alkanes and benzene are quite inert to oxidation with potassium permanganate in aqueous alkali. However, alkyl and aryl groups attached to benzene rings can be oxidized to carboxyl (-COOH) groups with hot, alkaline permanganate. For example. 

Alkanes are not particularly reactive they do not readily react with dilute acids, cdkaUs, or oxidizing agents such as potassium permanganate and sodium dichromate. They do, however, burn in a plentiful supply of oxygen to form carbon dioxide and water ... 

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