Oxidizing agents peracids

Cyclopropyl ketones have been converted into alkyl cyclopropanecarboxylates using various oxidizing agents. Peracids, such as peracetic acid, 3-chloroperoxybenzoic acid, and tri-fluoroperacetic acid, have been most frequently utilized, ° but the reaction has also been carried out photochemically. A severe problem can be concomitant formation of cyclopropyl carboxylates exo-4-trideuteriomethylbicyclo[3.1.0]hexan-2-one reacted with 3-chloroperoxybenzoic acid to give a significant amount of exo-5-trideuteriomethyl-2-oxabicyclo[4.1.0]heptan-3-one (12%) in addition to exo-5-trideuterio-methyl-3-oxabicyclo[4.1.0]heptan-2-one (49%). - ... 

The hydrides can also be used to form primary alcohols from either terminal or internal olefins. The olefin and hydride form an alkenyl zirconium, Cp2ZrRCl, which is oxidized to the alcohol. Protonic oxidizing agents such as peroxides and peracids form the alcohol direcdy, but dry oxygen may also be used to form the alkoxide which can be hydrolyzed (234). 

Isoxazoles are stable toward peracids and are fairly stable to other acidic oxidizing agents such as chromic and nitric acids, and acidic permanganate. 3-Substituted isoxazoles are... 

The oxidizing agent (organic peracid) usually attacks the sulfur from the less hindered side of the substrate to produce the less hindered oxidation product as a major isomer139. 

The oxidizing agent (organic peracid) usually attacks the sulfur from the less hindered side of the substrate to produce the less hindered oxidation product as a major isomer Thus, the observed stereoselectivity means the exclusive formation of the rmti-isomer (a). This conclusion was confirmed by NMR analysis (see Section III.B.4.b) and, clearly, can be extended and generalized with respect to larger cyclic sulfoxide systems. 

Alkylsulfonic acids are active oxidative agents like other organic peracids. Several oxidative reactions of seodecylsulfonic peracid were studied by Safiullin et al. [41]. Peracid was found to oxidize benzene to phenol as the first intermediate product. The formed sulfonic acid accelerates the reaction. Oxidation occurs according to the stoichiometric equation... 

The oxidation of both aliphatic and aromatic azo compounds to the corresponding azoxy derivative may be carried out with a variety of reagents. While older techniques favored chromic or nitric acid as the oxidizing agent, newer methods make use of various organic peracids or hydrogen peroxide. In the oxidation of aliphatic azo compounds, relatively weak peracids are favored to reduce the possibility of acid-catalyzed isomerization of azo compounds to hydrazones. Under controlled conditions cis azo compounds may be converted into cis azoxy compounds. 

Condensation of three thiophene rings, as in dithienothiophenes (5-10), results in a greater reactivity toward oxidizing agents such as peracids, the sulfur atom of the central ring being attacked.121,123,124 Dithieno[3,2-b 2, 3 -d]thiophene (6) and dithieno[3,4-6 3, 4 -[Pg.200]

Mechanisms of Aldehyde Oxidation. There must be at least two paths for oxidation of aldehyde to acid, and at least one of these must be temperature dependent. One pathway is the ozone-oxygen oxidation of aldehydes to peracids (14). However, peracid can also serve as an oxidizing agent for aldehyde. In the oxidation of acetaldehyde, Reaction 3 is thought to occur (14). 

The epoxidation of an alkene is clearly an oxidation, since an oxygen atom is added. Peroxyacids are highly selective oxidizing agents. Some simple peroxyacids (sometimes called peracids) and their corresponding carboxylic acids are shown next. 

We dealt in detail earlier in the chapter with reducing agents and their characteristic chemoselectivi-ties. Oxidizing agents are equally important, and in the chapter on electrophilic addition to alkenes we told you about peracids as oxidizing agents for C=C double bonds—they give epoxides. But... 

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