Peroxides peroxy esters

Hydroperoxides Organomineral Hydroperoxides a-Oxy and a-Peroxy-Hydroperoxides and Peroxides Ozonides Peroxides Peroxy Acids Diacyl Peroxides Peroxy Esters and Poly Peroxides... 

Since the first synthesis of the peroxyphosphoms ester 66 °, considerable efforts have been made to characterize the expanding chemistry of organophosphorus peroxy esters. Later, unsymmetrical phosphorus peroxides, such as peroxyphosphates 67 , peroxyphos-phonates 68 and peroxyphosphinates 69 , were reported. They can be prepared by the reactions of the chlorides and a tertiary carboxylic acid in the presence of base. 

Tetrahydroperoxycyclohexane Tetraacetate. C1SH28012 mw 436.46 OB to C02 —139.30% rhombic plates (from ethanol) mp 144—45° (decompn, then deton). Prepn is by reacting (caution) cyclodecandione (tetra) peroxide with ethanoyl chloride. The peroxy ester explds on gentle rubbing Refs 1) Beil, not found 2) R. Criegee H. Dietrich, Ann 560, 135-41 (1948) CA 43, 6189 (1949)... 

Azo compounds (diazenes) as sources of free radicals 19 Diacyl peroxides as radical sources 20 Peroxy esters 20... 

The Kharasch-Sosnovsky reaction may be carried out in the presence of carboxylic acids to introduce the acyloxy moiety of the acid used, and may also be conducted photochemically at room temperature using UV irradiation. Peioxy acids,diacyl peroxides, and peroxyphosphates and peroxyphospho-nates are alternative oxidants. /-Butyl hydroperoxide may also be used in place of peroxy esters with broadly similar results, although formations of mixed peroxides and /-butyl ethers can then compete with allyl ester production. 

Selenoxides are useful intermediates in the preparation of a,3-unsat-urated carbonyl compounds and esters. The treatment of aldehydes, ketones, or esters with benzeneselenyl chloride, C6H5SeCl, followed by the oxidation of the selenides to selenoxides by hydrogen peroxide, peroxy acids, or sodium periodate, gives a,3-unsaturated aldehydes, ketones, or esters. Thus, dehydrogenation with the formation of a carbon-carbon double bond is accomplished under very mild conditions [167, 169] (equation 593). 

Wird die Zersetzung (A = 254 nm 12°) von Diacetyl-peroxid in Anwesenheit von N,N-Dimethyl-acetamid durehgefiihrt, so erhalt man naeh 2 Stdn. N-Methyl-N-acetoxymethyl-acetamid in 22%iger Ausbeute13. Bessere Ergebnisse (67% d.Th.) lassen sieh hier mit der photochemisehen Peroxy-ester-Reaktion erzielen14. Ahnliche Resultate werden mit der Peroxyester-Reaktion auch mit N,N-Dimethyl-formamid crhalten16 16. 

Oxidation of Alkenes to Oxirans, using Peroxides. The peroxide (15 R = OOH) is a useful oxidant for a number of alkenes, giving epoxides in good to moderate yields and generating (15 R = OH). The reactivity of this peroxide is two orders of magnitude lower than that of peroxyacetic acid but at least one order of magnitude greater than that of a-peroxy-esters and -nitriles. Its selectivity relative to the structure of the alkene is similar to that for peroxyacetic acid. 

Peroxide (e.g., peroxy acid, peroxy ester, hydroperoxide) -0-0- Benzoyl peroxide... 

Chem. Descrip. Pivalic acid CAS 75-98-9 EINECS/ELINCS 200-922-5 Uses Intermediate for prod, of pivaloyl chloride (used as intermediate in prod, of peroxides and peroxy-esters for polymer prod.), and esters for use in coatings, lubricants, transmission fluids, photochemicals, cosmetics... 

Peroxy acids and diacyl peroxides are mono- and di-acyl derivatives of hydrogen peroxide. Peroxy acids form esters of which the t-butyl compounds are the best known. In contrast to carboxylic acids which form intermolecular hydrogen-bonded dimers, the peroxy acids exist as intramolecular hydrogen-bonded monomers. This leads to several differences in the properties of these two types of acids. 

AZ -H 2 Peroxy acids H3C[CH2] C03H Peroxy esters H3C[CH2],C03Bu Diacyl peroxides [H3C[CH2],C00]2 Diperoxy acids H03C[CH2] C03H... 

Vanadium special for ketone peroxide, hydroperoxide, and peroxy esters, giving short gel times, and very high cure speed. 

Controlled thermal degradation of polyolefins in the presence of peroxides has been carried out in extruders or in continuous mixers, to reduce polymer MW and sample polydispersity. The resulting material has more processing advantages than the undegraded one. Based on the same principle, random chemical functionalization of polyolefins with polar groups has been achieved by extruding the polymer in the presence of peroxy ketals or peroxy esters [29]. 

For initiation and molecular weight control in free radical polymerization of ethylene, a combination of several substances can be applied. Typically used free radical initiators belong to the classes of di-alkyl peroxides, peroxy alkyl esters, peroxy-carbonates, or di-acyl peroxides. The choice of the initiator mainly depends on its half lifetime at application temperature. To generate a more or less constant radical concentration level over a wide range of temperatures (e.g., 150-300 °C), a combination of different initiators is commonly applied. A typical mixture consists of a low and high temperature decomposing peroxide dissolved in hydrocarbons. 

The mechanism of the chemiluminescent decomposition of secondary peroxy-esters shows similar features [7], in that the loss of the secondary proton allows electron transfer to the activator radical cation. Activators are fluorescent compounds of low ionisation potential. In the example shown below the activator is not consumed, and the products, acetophenone and acetic acid, are formed quantitatively. The unactivated decomposition is very closely related to peroxide decomposition generally, and it is not surprising to find that the quantum yield is very low. 

Hydrolysis of Peroxycarboxylic Systems. Peroxyacetic acid [79-21-0] is produced commercially by the controlled autoxidation of acetaldehyde (qv). Under hydrolytic conditions, it forms an equiHbrium mixture with acetic acid and hydrogen peroxide. The hydrogen peroxide can be recovered from the mixture by extractive distillation (89) or by precipitating as the calcium salt followed by carbonating with carbon dioxide. These methods are not practiced on a commercial scale. Alternatively, the peroxycarboxyHc acid and alcohols can be treated with an estetifying catalyst to form H2O2 and the corresponding ester (90,91) (see Peroxides and peroxy compounds). 

Solid Peroxygen Compounds. Hydrogen peroxide reacts with many compounds, such as borates, carbonates, pyrophosphates, sulfates, sihcates, and a variety of organic carboxyHc acids, esters, and anhydrides to give peroxy compounds or peroxyhydrates. A number of these compounds are stable sohds that hydrolyze readily to give hydrogen peroxide in solution. 

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