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The selenoxide elimination has been used in converting ketones, esters, and aldehydes to their α,β-unsaturated derivatives. [1] [17] The mechanism for this reaction is analogous to the sulfoxide elimination, which is a thermal syn elimination through a 5-membered cyclic transition state. Selenoxides are preferred for this type of ...
Selenoxide elimination (also called α-selenation) [1] is a method for the chemical synthesis of alkenes from selenoxides. It is most commonly used to synthesize α,β-unsaturated carbonyl compounds from the corresponding saturated analogues. [ 2 ]
In contrast to sulfoxides, the corresponding selenoxides are unstable in the presence of β-protons and this property is utilized in many organic reactions of selenium, notably in selenoxide oxidations and in selenoxide eliminations. The first organoselenium compound to be isolated was diethyl selenide in 1836. [5] [6]
The sulfoxide in sulfur chemistry is represented in selenium chemistry by the selenoxides (formula RSe(O)R), which are intermediates in organic synthesis, as illustrated by the selenoxide elimination reaction. Consistent with trends indicated by the double bond rule, selenoketones, R(C=Se)R, and selenaldehydes, R(C=Se)H, are rarely observed.
The Chugaev elimination is a chemical reaction that involves the elimination of water from alcohols to produce alkenes.The intermediate is a xanthate.It is named for its discoverer, the Russian chemist Lev Aleksandrovich Chugaev (1873–1922), who first reported the reaction sequence in 1899.
Pyrolysis can also be used to treat municipal solid waste and plastic waste. [4] [17] [72] The main advantage is the reduction in volume of the waste. In principle, pyrolysis will regenerate the monomers (precursors) to the polymers that are treated, but in practice the process is neither a clean nor an economically competitive source of monomers.
There is no antiperiplanar requirement. An example is the pyrolysis of a certain sulfonate ester of menthol: E1 elimination Nash 2008, antiperiplanar relationship in blue Only reaction product A results from antiperiplanar elimination. The presence of product B is an indication that an E1 mechanism is occurring. [3]
In the second step, the selenide is oxidized with hydrogen peroxide to give a selenoxide. This structure decomposes to form an alkene by an E i elimination mechanism with expulsion of a selenol in a fashion similar to that of the Cope elimination. This reaction takes part in the synthesis of ring C of the Danishefsky Taxol synthesis.