Ketones, the Baeyer-Villiger Oxidation

Using Figure 17 15 as a guide write a mechanism for the ] Baeyer-Villiger oxidation of cyclohexyl methyl ketone by peroxybenzoic acid J... 

The Baeyer-Villiger oxidation of ketones to esters (or lactones) occurs by the following mechanism. 

FIGURE 17.15 Mechanism of the Baeyer-Villiger oxidation of a ketone. 

Section 17.16 The oxidation of ketones with peroxy acids is called the Baeyer-Villiger oxidation and is a useful method for preparing esters. 

Compounds known as lactones, which are cyclic esters, are formed on Baeyer—Villiger oxidation of cyclic ketones. Suggest a mechanism for the Baeyer—Villiger oxidation shown. 

When a ketone 1 is treated with hydrogen peroxyde or a peracid, a formal insertion of oxygen can take place to yield a carboxylic ester 2. This process is called the Baeyer-Villiger oxidation ... 

The Baeyer-Villiger oxidation is a synthetically very useful reaction it is for example often used in the synthesis of natural products. The Corey lactone 11 is a key intermediate in the total synthesis of the physiologically active prostaglandins. It can be prepared from the lactone 10, which in turn is obtained from the bicyclic ketone 9 by reaction with m-chloroperbenzoic acid (MCPBA) " ... 

The action of aqueous potassium hydroxide on chloronitrile 14 in DMSO at 25-30°C accomplishes the hydrolysis of the chloronitrile moiety and furnishes ketone 13 in a yield of 80%. Treatment of a solution of ketone 13 in CH2CI2 with mCPBA and sodium bicarbonate results in a selective Baeyer-Villiger oxidation to give bicyclic lactone 12 in >95% yield. It is noteworthy that the Baeyer-Villiger oxidation is completely regioselective and that the... 

Hassall, C. W., The Baeyer-Villiger oxidation of aldehydes and ketones. Organic Reactions. 9, 73-106, 1957. 

The Baeyer-Villiger oxidation reaction was discovered more than 100 years ago by Adolf von Baeyer and Victor Villiger. By this reaction, ketones are converted into the corresponding esters. In organic chemistry, peracids are commonly used as catalyst to perform this atypical oxidation reaction that results in oxygen insertion into a carbon—carbon bond (Fig. 1). 

For the oxidation of ketones, Baeyer-Villiger oxidation of cyclic ketones with monopersuccinic acid in water gives lactones in good results (Eq. 8.22).47 Peroxy species generated from borax in 30% hydrogen peroxide is effective for the Baeyer-Villiger oxidation of... 

Since the polyleucine epoxidation conditions are only favourable for highly electron-deficient unsaturated systems (i. e. ketones), use of the Baeyer-Villiger oxidation subsequent to the epoxidation reaction allows access to the optically active epoxyesters. 

In 1998, Strukul and coworkers presented a diphosphine-palladium complex, with which the Baeyer-Villiger oxidation of cyclic and for the first time also acyclic ketones could be catalyzed in the presence of various peroxidic oxidants (H2O2, TBHP, KHSO5, carbamide peroxide) (Scheme 158)4 . pj-om these oxidants H2O2 turned out to be the most efficient one, whereas almost no conversion was obtained (<1% after several days) with TBHP. The authors could show that an increase in the bite angle of the diphosphine caused... 

Mechanism of Baeyer-Villiger Oxidation Both aldehydes and ketones are oxidized by peroxy acids. This reaction, called the Baeyer- Villiger oxidation, is especially useful with ketones. 

The Baeyer-Villiger oxidation of cyclic ketones was also achieved by the MTO/H2O2 system in the ionic liquid [BMIM][BF4 [78] (Scheme23). Kinetic investigations have additionally been performed in order to follow the formation of the catalytically active peroxorhenium intermediates in the RTILs [81,82]. 

The Baeyer-Villiger oxidation of ketones represents a powerful synthetic method that breaks carbon-carbon bonds in an oxygen insertion process to deliver lactones. A recent comprehensive review by ten Brink et describes the different... 

The Baeyer-Villiger oxidation of 3-trimethylsilylcyclohexanone [250] is regioselec-tive as indicated. The reason for the selectivity is electronic which is revealed by an examination of the relationship between the polar groups of the ketone. Here we find a disjoint sequence, the a and f) carbon atoms are both quasidonors as dictated by their respective neighbors. The observed rearrangement, but not the alternative mode, relieves the unfavorable electronic interactions. 

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