Peroxyacids formation

Dor the correct interpretation of the phenomena taking place in the radiolysis of sulfuric acid solutions, a good understanding of the radiolytic behavior of the peroxysulfuric acids, as well as of the ultimate fate of the sulfate radicals is necessary. In fact, the peroxyacids of sulfuric acid are formed during radiolysis with yields which depend on the H2S04 concentration (I, 4). In aerated solutions this peroxyacid formation has been considered as the net result of Reactions 1 to 5 ... 

The findings prove that peroxyacid oxidizes the reaction product from 2 to 3 moles of PMSA ai e spent per 1 mole of RP. If the components ai e mixed unintermptedly, the output of RP does not depend on the order of mixing. Value of (1.2-1.3)xl0 mole -cm -1 is close to values, given for other oxidants. At the sui plus of H Dm compai ed to nickel (6 1)3 moles of PMSA ai e spent per 1 mole of RP, while at the sui plus of PMSA (10 1) 3 moles of H Dm ai e spent per 1 mole of RP. The data obtained do not let us affirm what exactly oxidize in the RP - Ni(II) or H Dm. It is proved, that under conditions of formation, RP is not oxidized by PMSA. 

Destruction of the aromatic ring is the mam reaction in the oxidation of tetrafluoro-o phenyleiiediamine with lead tetraacetate by products are tetrafluorobenzotnazole and tetrafluorochinoxalme denvatives [92] (equation 85) Polyfluonnated benzylideneanilines are oxidized by peroxyacids to different products dependmg on reaction contitions at room temperature the benzylidene carbon is oxidized with the formation of peroxy bonds [93 94] (equation 86), whereas in refluxing agent, the azomethme bond is cleaved [93] (equation 86) Pentafluorobenzylidencanilme is oxidized by peroxyacetic acid in dichlo-romethane at room temperature to perfluorobenzoic acid in a 77% yield [93]... 

A process that is effective for epoxidation and avoids acidic conditions involves reaction of an alkene, a nitrile, and hydrogen peroxide.82 The nitrile and hydrogen peroxide react, forming a peroxyimidic acid, which epoxidizes the alkene, by a mechanism similar to that for peroxyacids. An important contribution to the reactivity of the peroxyimidic acid comes from the formation of the stable amide carbonyl group. 

Dining an attempt to prepare an anhydrous 25% solution of peroxyacetic acid in acetic acid by dehydrating a water-containing solution with acetic anhydride, a violent explosion occurred. Mistakes in the operational procedure allowed heated evaporation to begin before the anhydride had been hydrolysed. Acetyl peroxide could have been formed from the anhydride and peroxyacid, and the latter may have detonated and/or catalysed violent hydrolysis of the anhydride [1], A technique for preparing the anhydrous acid in dichloromethane without acetyl peroxide formation has been described [2],... 

See other PACKAGING INCIDENTS, PEROXYACIDS 0834. Hydroperoxymethyl formate (Formyloxymethyl hydroperoxide)... 

You are already familiar with the simple formation of epoxides 26 by the action of peroxyacids such as mCPBA on alkenes 27. They can equally well be made by cyclisation of chloro-alcohols 25 as in the Comforth addition of a Grignard reagent to an a-chloroketone and cyclisation in base.3... 

Formation of an epoxide, usually from an alkene. A peroxyacid is generally used for alkene epoxidations. (p. 360)... 

Another route to the preparation of a-hydroxy derivatives consists of the transformation of enolates into silyl enolates and their subsequent oxidation. Oxidation of triaLkylsUyl enolates with peroxyacids, most frequently cpba, has been applied for preparation of a-hydroxy- and a-acetoxy aldehydes or ketones. Reactions require mild conditions and generally give good yields of the expected compound . Mechanistic investigations suggest the intermediate formation of epoxides which evolve to the final products via 1,4-sUyl group migration. 

Epoxidation occurs via the concerted addition of one oxygen atom of the peroxyacid to the k bond as shown in Mechanism 12.4. Epoxidation resembles the formation of the bridged halo-nium ion in Section 10.13, in that two bonds in a three-membered ring are formed in one step. 

The epoxidation reaction of arene oxide-oxepins has been encountered in the formation of the arene dioxides of naphthalene and anthracene rings A similar approach to the synthesis of epoxides of benzene oxide-oxepin using a peroxyacid oxidant, however, was unsuccessful (Z,Z)-muconaldehyde was isolated presumably via an oxepin-epoxide intermediate. The disubstituted benzene... 

Write a balanced equation for the reaction of propene with a general peroxyacid, RC020H, given that such a reaction results in the formation of the epoxide. 

Generally, chemists prefer the peroxyacid method of epoxide formation to the halohydrin method. Reactions (a) and (b) show the peroxyacid method, but the halohydrin method could also be used. 

On the other hand, the very low values of G( S2082") lead us also to conclude that, in 0.4M H2S04 solutions, the measured yield of peroxydisulfate formation is small not on account of a radical attack on the peroxyacid (15) but because its formation yield is low. In other words,... 

This preparation, illustrating the formation of the salt of a peroxyacid from hydrogen peroxide, is to be compared with Experiment 48, where the peroxysalt is formed electrolytically. 

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