Potassium permanganate fluoroalkenes

Perfluoroepoxides have also been prepared by anodic oxidation of fluoroalkenes (39), the low temperature oxidation of fluoroalkenes with potassium permanganate (40), by addition of difluorocarbene to perfluoroacetyl fluoride (41) or hexafluoroacetone (42), epoxidation of fluoroalkenes with oxygen difluoride (43) or peracids (44), the photolysis of substituted l,3-dioxolan-4-ones (45), and the thermal rearrangement of perfluorodioxoles (46). 

Hydroxylation of a 1-ethoxy-1-fluoroalkene by potassium permanganate followed by spontaneous elimination of hydrogen fluoride from the initial product 58 gives the ethyl 2-hydroxy-carboxylate 59.94... 

In accordance with this scheme, internal fluoroalkenes are oxidized by potassium permanganate, under strictly controlled conditions, with preservation of the C-C bond to give aliphatic or alicyclic fluorine-containing a-dicarbonyl and a-hydroxycarbonyl compounds. 

Unsaturated halogenated compounds with a central C = C or C = C bond undergo cleavage on oxidation in the middle of the molecule and form two carboxylic acids without loss of a carbon atom. The reaction mechanism of the oxidation of internal fluoroalkenes by potassium permanganate includes hydroxylation of the C = C bond in 2 by permanganate, accompanied by dehydrofluorination of the geminal fluoroalkane-1,2-diol 3 and formation of an intermediate fluorocarbonyl compound 4 oxidative cleavage of the C-C bond in 4 leads to the final products 5.1... 

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