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The radicals formed from alkenyl peroxides can be utilized in organic radical reactions. For example, they can mediate hydrogen atom abstraction reactions and thus lead to the functionalization of C-H bonds, [7] or they can be used to introduce ketone residues by addition of the alkenyloxyl radicals to alkenes. [8] [9] [10]
The Milas hydroxylation is an organic reaction converting an alkene to a vicinal diol, and was developed by Nicholas A. Milas in the 1930s. [1] [2] The cis-diol is formed by reaction of alkenes with hydrogen peroxide and either ultraviolet light or a catalytic osmium tetroxide, [3] vanadium pentoxide, or chromium trioxide.
The mechanism of the Wharton reaction. The Wharton olefin synthesis allows the transformation of an α,β unsaturated ketone into an allylic alcohol. The epoxide starting material can be generated by a number of methods, with the most common being reaction of the corresponding alkene with hydrogen peroxide or m-chloroperoxybenzoic acid. The ...
Whereas many hydroxylations insert O atoms into C−H bonds, some reactions add OH groups to unsaturated substrates. The Sharpless dihydroxylation is such a reaction: it converts alkenes into diols. The hydroxy groups are provided by hydrogen peroxide, which adds across the double bond of alkenes. [12]
Alkenes react with percarboxylic acids and even hydrogen peroxide to yield epoxides: RCH=CH 2 + RCO 3 H → RCHOCH 2 + RCO 2 H. For ethylene, the epoxidation is conducted on a very large scale industrially using oxygen in the presence of silver-based catalysts: C 2 H 4 + 1/ 2 O 2 → C 2 H 4 O. Alkenes react with ozone, leading to the scission ...
The Schenck ene reaction or the Schenk reaction is the reaction of singlet oxygen with alkenes to yield hydroperoxides. The hydroperoxides can be reduced to allylic alcohols or eliminate to form unsaturated carbonyl compounds. It is a type II photooxygenation reaction, and is discovered in 1944 by Günther Otto Schenck. [1]
[3]: 188, 751 The result is typically anti-Markovnikov addition, a phenomenon Morris Kharasch called the "peroxide effect". [4] Reaction is slower with alkynes than alkenes. [3]: 750 In the paradigmatic example, hydrogen bromide radicalyzes to monatomic bromine. These bromine atoms add to an alkene at the most accessible site, to give a ...
The use of hydrogen peroxide can produce carboxylic acids. Amine N-oxides produce aldehydes directly. [8] Other functional groups, such as benzyl ethers, can also be oxidized by ozone. It has been proposed that small amounts of acid may be generated during the reaction from oxidation of the solvent, so pyridine is sometimes used to buffer the ...