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The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. [1] The heating of an allyl vinyl ether will initiate a [3,3]-sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, driven by exergonically favored carbonyl CO bond formation Δ(Δ f H) = −327 kcal/mol (−1,370 kJ/mol).
The Ireland–Claisen rearrangement is a type of Claisen rearrangement. The mechanism is therefore a concerted [3,3]-sigmatropic rearrangement which according to the Woodward–Hoffmann rules show a concerted, suprafacial, pericyclic reaction pathway.
An example of Claisen rearrangement is the [3,3] rearrangement of an allyl vinyl ether, which upon heating yields a γ,δ-unsaturated carbonyl. The formation of a carbonyl group makes this reaction, unlike other sigmatropic rearrangements, inherently irreversible.
The mechanism of the thermal Claisen rearrangement has been studied by crossover experiment and serves as an excellent example of how to apply this technique. [9] Before the mechanism was determined, it was proposed that the reaction could proceed via an intermolecular or intramolecular route. [1]
The Claisen condensation is a carbon–carbon bond forming reaction that occurs between two esters or one ester and another carbonyl compound in the presence of a strong base. The reaction produces a β-keto ester or a β-diketone. [1] It is named after Rainer Ludwig Claisen, who first published his work on the reaction in 1887.
The reaction is known as the Claisen reaction and was described by Claisen for the first time in 1890. Discovered the thermally induced rearrangement of allyl phenyl ether in 1912. He details its reaction mechanism in his last scientific publication (1925). In his honor, the reaction has been named the Claisen rearrangement.
"The targeted location of the brain they were stimulating, the hypothalamus, has not historically been known to be involved in the mechanism of gait," Murray, who was not involved in the study ...
An allyl alcohol and a vinyl ether under the conditions of oxymercuration–reaction can give R–CH=CH–CH 2 –O–CH=CH 2, which is suitable for a Claisen rearrangement. [8] Mercury-catalyzed enol ether exchange Mechanism mercury-catalyzed enol ether exchange