Oxidation of ethers

The conversion of primary alcohols and aldehydes into carboxylic acids is generally possible with all strong oxidants. Silver(II) oxide in THF/water is particularly useful as a neutral oxidant (E.J. Corey, 1968 A). The direct conversion of primary alcohols into carboxylic esters is achieved with MnOj in the presence of hydrogen cyanide and alcohols (E.J. Corey, 1968 A,D). The remarkably smooth oxidation of ethers to esters by ruthenium tetroxide has been employed quite often (D.G. Lee, 1973). Dibutyl ether affords butyl butanoate, and tetra-hydrofuran yields butyrolactone almost quantitatively. More complex educts also give acceptable yields (M.E. Wolff, 1963). 

Explosions due to the presence of peroxides formed by aerial oxidation of ethers and tetrahydrofuran, decahydronaphthalene, acrylonitrile, styrene and related compounds. 

The oxidation of ethers to esters according to the reaction offers many possibilities for the modification of functionality in open chain or cyclic systems. An example is the... 

Oxidation of Ethers to Carboxyiic Esters and Related Reactions... 

The oxidation of ethers by dioxygen is very similar to hydrocarbon oxidation. The following three peculiarities of ethers can be mentioned since they influence the mechanism of their oxidation by dioxygen. 

The mechanism and kinetics of ether oxidation are discussed in monographs [7-10], The valuable information about the chemistry of ether oxidation is given in Ref. [8]. The photo-and radiation-induced oxidation of ethers are described. 

L. Gosalvi, 1. W. C. E. Arends, P. Moilanen, R. A. Sheldon, The Effect of pH Control on the Selective Ruthenium-Catalyzed Oxidation of Ethers and Alcohols with Sodium Hypochlorite, Synth Catal. 345 (2003) 1321—1328. 

The reagent most commonly used for oxidation of ethers is RuO, and esters or lactones are the main prodncts early results are weU summarized by Gore [35], The first such oxidation of an ether was in 1958 when n-butylether gave n-butyl-n-... 

Fig. 1.11 Reaction scheme for stoicheiometric oxidation of ethers to esters by RuO [388]...

Abstract This chapter principally concerns oxidations of organic substrates containing N, O, S, P, As and Sb. Oxidations of amines are covered first, including primary amines to nitriles or amides secondary amines to imines or other products tertiary amines to N-oxides or other prodncts (Section 5.1) and the oxidation of amides (5.2). Oxidation of ethers to esters or lactones follows (5.3), then of sulfides to sulfoxides or sulfones (5.4) and of phosphines, arsine and stibines to their oxides (5.5). A final section (5.6) concerns such miscellaneous oxidations not covered by other sections in the book. 

The reagent most commonly used for oxidation of ethers is RuO. The subject is well summarized in an early review by Gore [75], Primary methyl ethers RCHjOCHj are oxidised to esters RCOOCH, and secondary methyl ethers R R CjHjOCHj to ketones R COR while with benzyl ethers PhCH OR the esters PhCOOR are formed. For cyclic ethers, the carbon atoms adjacent to the O atom are oxidised, and if there are two secondary carbon atoms the main products are lactones, sometimes with partial hydrolysis to carboxylic acids [75], There is a short review on oxidation of ethers by RuO, principally on the mechanisms involved [76],... 

Table 5.2 Oxidation of ethers to esters or lactones and suMdes to sulfoxides or sulfones... 

Chain Oxidation of Ethers Co-Oxidation of Ethers and Hydrocarbons Reactivity of Ethers in Reactions with Peroxyl Radicals... 

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