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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.
The Grieco elimination is an organic reaction describing the elimination reaction of an aliphatic primary alcohol through a selenide to a terminal alkene. [ 1 ] [ 2 ] It is named for Paul Grieco . The alcohol first reacts with o -nitrophenylselenocyanate and tributylphosphine to form a selenide via a nucleophilic substitution on the electron ...
In general, if more than one alkene can be formed during dehalogenation by an elimination reaction, the more stable alkene is the major product. There are two types of elimination reactions, E1 and E2. An E2 reaction is a One step mechanism in which carbon-hydrogen and carbon-halogen bonds break to form a double bond. C=C Pi bond.
In organic chemistry, the E i mechanism (Elimination Internal/Intramolecular), also known as a thermal syn elimination or a pericyclic syn elimination, is a special type of elimination reaction in which two vicinal (adjacent) substituents on an alkane framework leave simultaneously via a cyclic transition state to form an alkene in a syn elimination. [1]
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] It is mechanistically related to the Cope reaction.
The key mechanistic step of this process is elimination of an anionic or organometallic intermediate to generate the alkene. (6) The use of sodium amalgam, which promotes the formation of essentially free alkyl anions, [ 9 ] leads to ( E ) alkenes with extremely high selectivity.
When a small, unhindered base – such as sodium hydroxide, sodium methoxide, or sodium ethoxide – is used for an E2 elimination, the Zaytsev product is typically favored over the least substituted alkene, known as the Hofmann product. For example, treating 2-Bromo-2-methyl butane with sodium ethoxide in ethanol produces the Zaytsev product ...
Additionally, elimination using sodium or potassium hydride may not be feasible due to incompatible functional groups. Chan et al. have found that acylation of the intermediate silylcarbinol with either acetyl chloride or thionyl chloride gives a β-silyl ester that will eliminate spontaneously at 25 °C giving the desired alkene. [ 9 ]