Ozonolysis of olefins

By-products include ozonides (17). Other peroxidic products including polymeric peroxides and polymeric ozonides can form, depending on reaction conditions, solvent, and olefin used. A variety of cycHc diperoxides (4) have been obtained by ozonolysis of olefins. Both cis- and... 

Other oxidation chains can be constructed. For example, when methyl radicals are generated by other reactions, as in the ozonolysis of olefins, the following reactions can occur ... 

The ozonolysis of olefins has been studied for over 60 years, and is stiU the subject of current research. The principle interest lies in the complex mechanism of dipolar additions, chain scissions, and recombinations that are the source of the complexity... 

The carbonyl oxides, i.e. the carbon analogs of water oxide, are well-established intermediates in the ozonolysis of olefins and may be independently prepared by treatment of diazo compounds with singlet oxygen. ... 

The ozonolysis of olefins may be analyzed as a sequence of two 1,3-dipolar cycloadditions initial electrophilic attack by ozone 18 to form the first intermediate, which decomposes into a carbonyl compound and a carbonyl oxide 14 followed by nucleophilic... 

The alkoxyhydroperoxides, which are formed in the ozonolysis of olefins in alcohols, are electrochemically reduced to dialdehydes in very good yields 541 542> ... 

In contrast to this, very little is known about the ozonolysis of olefins which bear halogen substituents at the double bond. This is somewhat surprising since compounds containing vinyl halide moieties are important technical products whose properties could be adversely affected by ozone degradation. A case in point is neoprene rubber, whose performance as an elastomer could suffer considerably by ozone attack and concurrent crack formation (1). 

At high enough concentrations, PAN is a potent eye irritant and pliytotoxin. On a smoggy day in the Los Angeles area, PAN concentrations are typically 5 to 10 ppb in the rest of the United States PAN concentrations are generally a fraction of a ppb. An important formation route for formaldehyde [50-00-0]y HCHO, is reaction 9. However, ozonolysis of olefinic compounds and some other reactions of VOCs can produce HCHO and other aldehydes. 

Ozonolysis of olefins has found little application in the preparation of ketones for synthetic purposes. Since the ozonides may be explosive, the method has been limited to the reaction of small quantities of olefins, mostly for degradation studies and location of double bonds. 

Although a-dicarbonyl compounds are not known to be products of the ozonolysis of olefins, biacetyl has been isolated in photochemically initiated reactions 14, 15) which result in the net oxidation of olefins in the gas phase. For example, when a mixture of ci5-2-butene, nitric oxide, and air is irradiated, small amounts of biacetyl are isolated. One of the pathways suggested to explain the production of biacetyl involves the reaction of ozone with ci5-2-butene (14) ... 

Improved Synthesis of Aromatic Aldehydes from Ozonolysis of Olefins... 

Ozonides are reduced to alcohols by UAIH4 [MS3] and NaBH4 in alcohols [CH4, H3J. However, it appears that the best reagent is BHj MejS in CH2CI2 at room temperature, a method that is compatible with carboxylic esters [FGl] (Figure 2.26). Ozonolysis of olefins followed by reduction can be performed sequentially in a one-flask operation. 

Harries ozonolysis of olefins with oxidative workup Additive oxidation... 

Keul, H., Griesbaum, K. Ozonolysis of olefins containing monochloro substituted double bonds. Can. J. Chem. 58, 2049-2054 (1980)... 

Certain aldehydes and ketones, when used as solvents, intercept and reduce a labile intermediate in the ozonolysis of olefins. The intermediate, which can be considered the progenitor of many other ozonolysis products, is formulated as the Staudinger molozonide, e.g. (577), and its reduction generates the corresponding dioxetan (578) with a Baeyer-Villiger oxidation of the aldehyde or ketone solvent. The dioxetan intermediate, normally cleaved to the carbonyl components, has now been isolated and characterized by using pinacolone as a solvent. Low-temperature infrared studies of simple alkene-ozone reactions have been made. ... 

Esters are obtained from aldehydes by treatment with alcoholic potassium or lithium alkoxides and ozone at —78 While the method has obvious limitations, it looks sufficiently expedient to be of use with suitable substrates. The ozonolysis of olefins leads directly to esters when the reaction is carried out in the presence of an alcohol and anhydrous hydrogen chloride s or boron trifluoride in methanol. S ... 

Ozonolysis of olefins and the use of other oxidants such as permanganate, permanganate-periodate, dichromate-sulfuric acid, and hydrogen peroxide-lead tetraacetate are also useful in preparing ketones by cleaving the olefin into two fragments. 

White and Jayasinghe have reported a synthesis of integerrinecic acid lactone via anchimerically assisted opening of an epoxide [46] (Scheme 71). Ozonolysis of olefin 319, followed by oxidative work-up with Jones reagent, and subsequent... 

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