Oxidation to hydroperoxides

High selectivity of hydrocarbon oxidation to hydroperoxide can be performed with the heterogenous catalyst, which possesses... 

Empically found catalysts with high selectivity are known. The results on ethylbenzene oxidation to hydroperoxide with the Ag catalyst with different modifications of the surface (346 K, [catalyst] = 15 g L-1, p02 = 105 Pa [255]) are given below. 

ACD has been associated with ethoxylated alcohol surfactants. Though not by themselves known to cause ACD, ethoxylated surfactants are polyethers and are easily air oxidized to hydroperoxides, peroxides, and carbonyl compounds (including formaldehyde and acetaldehyde), substances that do cause ACDJ22 251 The irritant components of surfactants and other chemicals present in formulated products facilitate the absorption of the ACD causing decomposition products of ethoxylated alcohols and thus exacerbate their effects. F61 This is yet another example of lipophilic compounds enhancing the absorption of hydrophilic compounds (the decomposition products of ethoxylated alcohols) and hence increasing the toxic effect beyond that predicted. 

Use Solvents, synthetic-resin manufacture, metal polishes, organic synthesis (oxidation to hydroperoxides used as catalysts for synthetic-rubber manufacture cymene alcohols are made by hydrogenating the hydroperoxides). Purep-cresol and carvacrol are made from p-cymene. 

Oxidation. Ethylbenzene is oxidized to hydroperoxide by air injection in the liquid phase. This takes place simultaneously in several series of reactors in parallel, each containing three elements. These are empty vessels, generally of titanium, in which a residence time of abont one hour is maintained. In each series, these units operate at. decreasing temperature as the reaction advances. The heat liberated by the reaction is... 

Dibenzyl ether is oxidized to hydroperoxide which decomposes under mild conditions to benzaldehyde and benzyl alcohol [186—188,294], viz. 

High selectivity of cumene oxidation to hydroperoxide can be connected with possibility of formation of cumyl hydroperoxide, CH, in chain termination reaction [33]. 

These works appeared actually simultaneously with ours. In presence of heterogenised variable-valence metal compounds the values and of cumene oxidations to hydroperoxide are lower. For example, at catalysis by silica - and polymer (poly-4-vinylpyridine) - supported Cu(OAc)2, the increase in the rate of cumene oxidation by 68% was observed, and was equal 92% at C = 22% [36]. 

Really, it was established by us earlier that selectivity of cumene oxidation to hydroperoxide CH increased from 5 = 95% (in the uncatalyzed oxidation) up to = 97-98% in the presence of 6-10 mold Ni(II)(acac)2, while the conversion with the retention of is increased from 10 to 15% [17],... 

The dihydropyridine structure will readily oxidize to hydroperoxide, which can then break down into ketonic and aromatic structures (Scheme XIX)-... 

Acyl lipid constituents, such as oleic, linoleic and linolenic acids, have one or more allyl groups within the fatty acid molecule (cf. Table 3.7) and thus are readily oxidized to hydroperoxides. The latter, after subsequent degradation reaction, yield a great number of other compounds. Therefore, under the usual conditions of food storage, unsaturated acyl lipids cannot be considered as stable food constituents. 

Cumene is converted by a two-step, noncatalytic process into phenol and acetone. It is first oxidized to hydroperoxide with air at 5-10 atm in an alkaline solution at pH 8.5-10 and 90°-130°C. The hydroperoxide is then converted to phenol and acetone in either a homogeneous 0.1-2% sulfuric acid solution at 60°-65°C or a two-phase liquid mixture with 40% sulfuric acid at 50°C. 

---