Permanganate oxidation of alcohols

Precolumn derivatization with a solid-phase derivatizing precolumn has also been reported. Xie et al. (43) applied polymeric permanganate oxidations of alcohols and aldehydes for the production of UV-absorb-ing species. 

Triphase catalyst. Commercial neutral alumina can function as a triphase catalyst in solid-liquid-solid systems. It can catalyze displacement reactions as well as the permanganate oxidation of alcohols. 

The oxidation of alcohols to carbonyl compounds by permanganate proceeds most rapidly in basic solution and it is with this medium that the majority of kinetic studies have been performed. 

Oxidation of alcohols to carbonyl compounds is an important reaction. Stoichiometric oxidants such as chromates, permanganates and MO4 (M = Ru, Os) are the commonly used reagents [19a,59,60]. However, they are going out of favour increasingly because they create heavy metal wastes . In view of this, development of environmentally friendly heterogeneous catalysts for alcohol oxidation is very important. In the use of catalytic amounts of transition metal salts or complexes as homogeneous catalysts for the oxidation of alcohols [61-64], separation of the catalyst from the reaction mixture and its subsequent recovery in active form is cumbersome. Heterogeneous catalysts for this kind of reaction are therefore necessary [65]. Clearly, encapsulation and/or immobilization of known... 

Aldehydes are oxidized easily by moist silver oxide or by potassium permanganate solution to the corresponding acids. The mechanism of the permanganate oxidation has some resemblance to the chromic acid oxidation of alcohols (Section 15-6B) ... 

The selective oxidation of alcohols is widely recognized as one of the most fundamental transformations in both laboratory and industrial synthetic chemistry because the resulting carbonyl compounds serve as important and versatile intermediates for the synthesis of fine chemicals [4]. Many oxidizing reagents, including permanganate and dichromate, have traditionally been employed to achieve this transformation [5]. These stoichiometric oxidants, however, have serious... 

Lithium aluminum hydride reduction of pleiocarpinilam (CXLVI-D) and kopsinilam (CXLII-D) gave, respectively, N-methylkopsinyl alcohol (CXLVI-F) and kopsinyl alcohol (CXLII-F) and thus there was every likelihood that these alkaloids were the E-ring lactams derived from pleiocarpinine and kopsinine, respectively. The correctness of this view was shown by synthesis. Pleiocarpinilam was obtained by the direct permanganate oxidation of pleiocarpinine (CXLVI-A) in acetone, while kopsinilam could be prepared, in a similar manner, from N-acetyl-kopsinine (CXLIV-A) followed by acid hydrolysis of the acetyl group, or from pleiocarpine lactam A (CXLV-D) by hydrolysis and simultaneous decarboxylation of the X-carbomethoxyl followed by reesterification of the C-3 carboxylic acid. 

The permanganate or nitric acid oxidation of alcohols and ketones has proved to be equally popular.211-21S)... 

Oxidations of alcohols on solid potassium or sodium permanganate surfaces take place under mild conditions with high yield and easy workup. Solid sodium permanganate can also oxidize aldehydes and sulfides but not alkenes or alkynes the solid reagent is thus more selective than the oxidant in solution. Mechanistic aspects (including an observed need for trace quantities of water at the crystal surface,... 

The methyl ester of oxycellulose, produced by alkaline permanganate oxidation of cuprammonium cellulose followed by treatment with diazomethane, has been reacted with protein by the azide method [34]. Acidic oxyce]]uloses are aiso able to react with alcohols and amines, including proteins, to form esters or amide derivatives. 

The Cr(VI) oxidation of alcohols is acid catalyzed, but both under acidic or basic conditions permanganate effects the same transformation. 

With careful choice of reagent and reaction conditions, alkenes containing other functionalities can be selectively hydroxylated without complicating side reactions. For example, the oxidation may be carried out in the presence of ester, ether, sulfide, carboxylic acid, acetal, carbonyl, halo, alcohol and aryl groups. Regioselective hydroxylation is also possible in dienes in which one center is electron poor, and some selectivity is also found between isolated double bonds. For example, syn hydroxylation of diene (5) with a catalytic amount of osmium tetroxide and N-methylmorpholine N-oxide as the secondary oxidant gives diol (6) in 46% yield, and phase transfer catalyzed permanganate oxidation of diene (7) affords diol (8) in 83% yield. 

Alanine, a-amino- -butyric acid, and a-aminoisobutyric acid are prepared by permanganate oxidation of the N-benzoyl derivatives of the corresponding amino alcohols. The free amino acids are obtained from the benzoyl derivatives by hydrolysis with hydrochloric acid followed by treatment with aniline. Over-all yields for the four step process are 45-60%. 

Oxidation of alcohols by acidic, reagents gives appreciable quantities of ester formed from the acid obtained and the original alcohol. For this reason, alkaline permanganate is sometimes preferred. 

In nonaqueous media, the oxidation of alcohols to acids is accomplished in heterogeneous systems by refluxing primary alcohols with solid sodium permanganate monohydrate in hexane (equation 232). The reaction is applicable even to allylic alcohols [555]. 

Aqueous potassium permanganate is hardly ever used to tixidize secondary alcohols to ketones, because further oxidation of ketones to carboxylic acids occurs even under mild conditions (15-30 °C) [2247]. On the other hand, oxidations of alcohols to ketones are successfully accomplished... 

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