Oxidative cleavage of ozonides

The oxidative cleavage of ozonides leads to carboxylic acids. This cleavage is carried out by treatment of the crude ozonization product with alkaline silver oxide, potassium permanganate, or hydrogen peroxide solution,121 or with peracetic acid.122... 

The literature of this reaction to 1940 has been adequately reviewed. The emphasis up to that time was placed on obtaining higher yields of carbonyl compounds by hydrolysis of the ozonides. Several methods have been described for the oxidative cleavage of ozonides to acids. These procedures may prove valuable in the synthesis of certain acids. By adding the ozonide of 1-tridecene to an alkaline silver oxide suspension at 95°, a 94% yield of lauric acid is obtained. Decomposition of ozonides with 30% hydrogen peroxide is described for the preparation of 5-methyl-hexanoic acid (67%) from 6-methyl-l-heptene and of adipic acid (60%) from cyclohexene. A study of solvents for ozonolysis has been made. ... 

The oxidative cleavage of ozonides to carboxylic acids is achieved with hydrogen peroxide in sodium hydroxide solution [97], in formic acid... 

Beside being a source of C-22 chemicals, erucic acid is a natural source of C-13 and C-9 chemicals made by cleavage at the site of the double bond. Ozonolysis of erucic acid followed by oxidative cleavage of the ozonide to form brassylic acid (BA) and pelargonic acid (Chart I) has been demonstrated on the pilot plant scale.[2,3] Yield of 99% pure brassylic acid was 72 to 82% of theoretical. 

NOC1 and an alcohol 9-9 From ozonides 9-10 Oxidative cleavage of enol ethers 9-13 Reaction between carboxylic acids and lead tetraacetate 9-18 Oxidation of ethers 9-22 Oxidation of primary alcohols or aldehydes... 

If the reaction is carried out in an emulsion of sodium hydroxide and hydrogen peroxide, the ozonide inteimediaies are convoted to carboxylic acids directly, with a consequent increase in yields. Oxidative cleavage of y-hydroxyalkenes results in the formation of lactones in good yields (equation... 

Ozonides are hardly ever isolated. Rather, conversions to products of ozonolysis are carried out in the same reaction vessels see Oxidative Cleavage of Double Bonds, page 77). 

Better yields are often obtained when ozone is used for oxidative cleavage of olefins to carboxylic acids or of cycloalkenes to dicarboxylic acids. Olefinic double bonds are very much more easily attacked by ozone than are aromatic systems, so that arylethylene derivatives can be successfully treated with ozone without appreciable effect on the ring. If the ozonide which is formed initially is decomposed with water, the aldehyde is obtained together with hydrogen peroxide and other products ... 

For future labeling syntheses of potential biosynthetic precursors, as well as for preparation of monocyclic diketones 70, on a 100- to 1000-g scale, additional, nonbiomimetic syntheses to these important intermediates were elaborated (63) (see Scheme 14). The key step of the first synthesis was oxidative cleavage of suitably substituted dimethyl indenes 68, either directly with permanganate-periodate or via remarkably stable ozonides 69. The required indenes 68 could be prepared from esters 67, and thus from very cheap educts like methacrylic acid and... 

Ozonolysis (Sections 8.16B and 8.19) The oxidative cleavage of a multiple bond using O3 (ozone). The reaction leads to the formation of a cychc compound called an ozonide, which is then reduced to carbonyl compounds by treatment with dimethyl sulfide (M02S) or zinc and acetic acid. 

Oxidative cleavage of an alkene with ozone leads to an ozonide. Reductive workup with dimethyl sulfoxide or zinc and acetic acid gives ketones and/or aldehydes. Oxidative workup with hydrogen peroxide gives ketones and/or carboxylic acids. Oxidative cleavage of 1,2-diols with periodic acid or with lead tetraacetate gives aldehydes or ketones. 

Ozonolysis of lycopadiene followed by oxidative cleavage of the ozonide afforded 6,10,14-trimethylpentadecan-2-one thus establishing the C(14)-C(15) and C(18)-C(19) location of the unsaturations. Moreover, the optical rotation of this ketone was identical with that observed for the 6(R),10(R), 14-trimethylpentadecan-2-one obtained from ozonolysis of natural phytol this result allowed assignment of stereochemistry to the asymmetric centers. Therefore, lycopadiene (45) was identified as... 

Perfluoroalkyl ethylene, CF3(CF2CF2) CH=CH2, obtained by dehalogena-tion of perfluoroalkylethyl iodide, is treated with ozone to give ozonides. Oxidative cleavage of the ozonides with hydrogen peroxide yields perfluoroalkanoic acids [132]. 

It results from oxidative cleavage of - oleic acid and is produced in commercial quantities mainly by ->ozonolysis (2% ozone in a stream of oxygen - pelargonic acid as a diluent 25-40°C ozonides... 

Ozonation. Alkenes react readily with ozone to give oxidized compounds via cleavage of the n or the direct product of the reaction, are rarely isolated but are transformed in situ into synthetically useful products. Depending on the solvent used and the actual workup of the reaction mixture different products may be isolated.582-584,592 Although its use is inconvenient, ozone is widely employed in selective syntheses. A classical use of ozone is in the structure determination of natural compounds and polymers. 

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