Alkenes, with acids permanganate

Some of the earliest work in the oxidation of alkenes was performed by oxidation with potassium permanganate. Under acidic and neutral conditions the intermediately formed glycols are oxidized, generally leading to cleavage of the carbon-carbon bond. Thus, such procedures have seldom been synthetically applied to diene oxidation. One notable... 

Alkenes can be oxidatively cleaved with hot permanganate solution to give carboxylic acids and/or ketones (Fig.E). The products obtained depend on the substituents present on the alkene. 

Alkenes can be cleaved with potassium permanganate to produce carboxylic acids (Following fig.). A vinylic proton must be present, that is a proton directly attached to the double bond. 

Wiberg and Saegebarth also obtained fair yields of cyclopentane-13-dialddiyde from the oxidation of bicyclo[2.2.1]hept-2-ene under mild conditions (equation 18). However, the oxidation of unsaturated tertiary carbons to the corresponding ketones is much more typical. The reaction depicted in equation (19), where a trisubstituted double bond is cleaved to a ketone and a carboxylic acid, is exertqrlaty of the products that are normaUy produced when alkenes react with aqueous permanganate. ... 

For the oxidation with potassium permanganate in water it is necessary to use a phase-transfer catalyst to obtain high yields.The phase-transfer agents are generally quaternary ictra-alkylammoniiim or phosphonium salts in concentrations of about 0.5-5 mol % relative to the alkene. Using this method several carboxylic acids, such as tetrafluoro-3-iodopropanoic acid, perfluoroheptanoic acid. perfluoroundecanoic acid, perfluorononanoic acid, and pcrfluorooctanedioic acid can be prepared. In a similar way, 3-(perfluoro-1,l-dimethyl-butyl)prop-l-ene can be oxidized. ... 

Linear and cyclic haloalkenes react with potassium permanganate to give acids or diacids. In contrast, polyfluorinated alkenes with a vinylidene group form ketones. ... 

For the ozonolysis of linear alkenes only alk-l-encs should be used to avoid product mixtures as the resulting formaldehyde or formic acid are readily separated. This type of reaction is also a successful method for the preparation of perfluorinated carboxylic acids.The advantage over the oxidation with potassium permanganate is that the process does not form solid byproducts which are diflicult to separate. A disadvantage of this procedure is the fact that two reaction steps arc needed to obtain the required product. 

Sodium periodate (sodium metaperiodate), NaI04 (mp 300 °C dec), which is commercially available, is applied mainly in aqueous or aqueous-alcoholic solutions. Like the free periodic acid, sodium periodate cleaves vicinal diols to carbonyl compounds [762], This reaction is especially useful in connection with potassium permanganate [763, 764] or osmium tetroxide [765], Such mixed oxidants oxidize alkenes to carbonyl compounds or carboxylic acids, evidently by way of vicinal diols as intermediates. Sulfides are transformed by sodium periodate into sulfoxides [322, 323, 766, 767, 768, 769, 770, 771, 772], and selenides are converted into selenoxides [773]. Sodium periodate is also a reoxidant of lower valency ruthenium in oxidations with ruthenium tetroxide [567, 774],... 

Manganic acetate (manganese triacetate), Mn(OCOCH3)3, is prepared by refluxing a solution of manganese acetate tetrahydrate in acetic acid with potassium permanganate [S03]. This oxidant hydroxylates ben-zylic methylene groups [416] and forms lactones from terminal alkenes [803, 804] (see equation 88). 

Sodium permanganate monohydrate, NaMn04 H20, which is commercially available, is used for the oxidation of alkenes to carboxylic acids [834] and of alcohols to carbonyl compounds [SJ5], the conversion of sul-finic acids into sulfonic acids [836], and the selective oxidation of sulfoxides to sulfones (sulfides are not oxidized with sodium permanganate in dioxane solutions) 837. ... 

The results of some oxidations with potassium permanganate differ depending on the pH of the reaction. For example, stearolic acid gives 9,10-diketostearic acid at pH 7-7.5 (achieved with carbon dioxide) and azelaic acid on treatment at pH 12 [864]. In some reactions, potassium permanganate is used as a catalyst for oxidation with other oxidants, such as sodium periodate. Thus alkenes are cleaved to carbonyl compounds or acids via vicinal diols obtained by hydroxylation with potassium permanganate, followed by cleavage by sodium periodate [763, 552]. 

Alkenes may also be transformed into vicinal dicarbonyl compounds. The treatment of alkenes with selenium dioxide, although possible, does not give satisfactory yields [509]. Better results are obtained when unsaturated compounds such as oleic acid are oxidized with potassium permanganate buffered with acetic anhydride [861],... 

Alkenes and cycloaikenes with at least one halogen linked to the double bonds are oxidized in aqueous or acetone solutions with potassium permanganate to carboxylic acids via acyl chlorides. Such oxidations are frequently used to prepare highly fluorinated or perfluorinated carboxylic acids (equations 118-120) [535, 869, 874]. 

Hydroxylation at double bonds of unsaturated carboxylic acids is accomplished stereoselectively by the same reagents as those used to hy-droxylate alkenes. syn Hydroxylation is carried out with potassium permanganate [101] or osmium tetroxide with hydrogen peroxide [130], sodium chlorate [310, 715], potassium chlorate [715], or silver chlorate [310] as reoxidant, anti Hydroxylation is achieved with peroxyacids, such as peroxybenzoic acid [310] or peroxyformic acid, prepared in situ from hydrogen peroxide and formic acid [101] (equation 472). 

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