Hydroxylations of double bonds

Fluonnated alkenes with one fluonne atom attached to the double bond are converted to a-hydroxyketones by potassium permanganate [30] (equation 22) a-Diketones are formed by permanganate hydroxylation of double bonds flanked by fluonne atoms [31] (equation 23)... 

The most important applications of peroxyacetic acid are the epoxi-dation [250, 251, 252, 254, 257, 258] and anti hydroxylation of double bonds [241, 252, the Dakin reaction of aldehydes [259, the Baeyer-Villiger reaction of ketones [148, 254, 258, 260, 261, 262] the oxidation of primary amines to nitroso [iJi] or nitrocompounds [253], of tertiary amines to amine oxides [i58, 263], of sulfides to sulfoxides and sulfones [264, 265], and of iodo compounds to iodoso or iodoxy compounds [266, 267] the degradation of alkynes [268] and diketones [269, 270, 271] to carboxylic acids and the oxidative opening of aromatic rings to aromatic dicarboxylic acids [256, 272, 271, 272,273, 274]. Occasionally, peroxyacetic acid is used for the dehydrogenation [275] and oxidation of aromatic compounds to quinones [249], of alcohols to ketones [276], of aldehyde acetals to carboxylic acids [277], and of lactams to imides [225,255]. The last two reactions are carried out in the presence of manganese salts. The oxidation of alcohols to ketones is catalyzed by chromium trioxide, and the role of peroxyacetic acid is to reoxidize the trivalent chromium [276]. 

Oxidations with peroxybenzoic acid are carried out in solutions in dichloromethane, chloroform, benzene, ether, or ethyl acetate at or below room temperature and include epoxidation of double bonds [295, 296, 297, 298, 299, 300, 301], oxidation of benzaldehydes to carboxylic acids or phenols [302], the Baeyer-Villiger reaction of ketones [303, 304, 305, 306, 307], and oxidation of sulfides to sulfoxides [308, 309]. Peroxybenzoic acid is also used for the anti hydroxylation of double bonds [310], the oxidation of pyrrolidines to pyrrolidones [377] and of pyrroles to succinimides [377], and the preparation of azoxy compounds from azo compounds [372]. 

Such oxidants cause the syn hydroxylation of double bonds [310, 714, 715, 716] and convert triple bonds into vicinal carbonyls [717]. Other applications, such as the conversion of furfural into fumaric acid [716, 718] or the oxidation of hydroquinone to quinone [719], are rare. 

Both complexes are used in the hydroxylation of double bonds via diacetates or dibenzoates of vicinal diols. The reaction is stereospecific. In anhydrous medium (the Privost reaction [783]), the reaction takes place in the anti mode. In the presence of water (the Woodward modification [783]), the reaction results in a syn addition. The mechanisms of both reactions are shown in the section Hydroxylation of Alkenes and Cycloal-kenes in Chapter 3 see equation 78). 

Potassium manganate, K2Mn04, purple crystals similar to potassium permanganate [529], forms a dark-green aqueous solution [830]. It is prepared from potassium permanganate and potassium hydroxide at 100 °C [830] or 120-140 °C [529]. Its use is limited to the syn hydroxylation of double bonds [529] and the hydroxylation of tertiary carbons in branched carboxylic acids [830, 557]. It offers no advantages over potassium permanganate. 

The main applications of chiral oxidations are the epoxidation of double bonds, especially in allylic alcohols [221, 222, 223, 1026, 1027, 1028, 1030, 1031], the hydroxylation of double bonds [951, 1033] and of the a position with respect to an ester group [1032], and the oxidation of non-symmetrical sulfides to chiral sulfoxides [224, 1025, 1029]. Optical yields (enantiomeric excesses [ee]) are frequently over 95%. 

Enantioselective hydroxylation of double bonds also occurs in biochemical oxidation by Pseudomonas putida [1073]. 

The carbon-carbon bond between two vicinal free hydroxyl groups can be cleaved to give two carbonyl compounds. This reaction is invaluable in the structure determination and transformation of sugars. In connection with hydroxylation of double bonds, it can be used as an alternative to the cleavage of double bonds by ozone [95i] (see equation 305). 

In combination with a catalytic amount of osmium tetroxide in t-butanol-pyridine, the reagent effects oxidative hydroxylation of double bonds."... 

The idea was extended by Feldman to vinylcyclopropane derivatives [30], The chemical conversion of C20 polyunsaturated fatty acid into prostaglandin backbone developed by Corey represents a pertinent and elegant illustration of the previous studies [31]. This chemistry is presented in Volume 2, Chapters 5.3 and 5.4. Therefore, we have limited our account to hydroxylation of double bonds by conversion to organometallic intermediates. 

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