Asked by: Whitney Miller
What is the Claisen-Schmidt condensation reaction?
The Claisen-Schmidt condensation reaction is an organic reaction in which a ketone or an aldehyde holding an α-hydrogen reacts with an aromatic carbonyl compound which does not have any α-hydrogens. This reaction is named after the chemists J.G. Schmidt and Rainer Ludwig Claisen.
Which is an example of claisen Schmidt reaction?
Claisen Schmidt condensation: When a base-catalyzed cross aldol condensation between an aromatic aldehyde and an aliphatic aldehyde or a ketone is called Claisen Schmidt condensation or simply Claisen reaction. For example, Benzaldehyde reacts with Acetaldehyde to form 3-Phenylprop-2-en-1-al.
What is Claisen condensation with example?
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, resulting in a β-keto ester or a β-diketone. It is named after Rainer Ludwig Claisen, who first published his work on the reaction in 1887.
What is the Claisen Schmidt reaction used for?
The Claisen-Schmidt reaction (crossed-aldol reaction) is a condensation reaction of aldehydes and carbonyl compounds leading to β-hydroxycarbonyl compounds and it has played an important role in synthetic organic chemistry [1,2,3,4,5,6].
Why is Claisen condensation important?
Claisen Condensation of Thioesters: A Biochemical Process
A variation on the Claisen condensation is an important biochemical reaction responsible for carbon–carbon bond formation in the biosynthesis of fatty acids. Also, a reverse Claisen condensation occurs in the catabolism of fatty acids.
What is the starting material used in claisen-Schmidt reaction?
The most widely used base catalyst is NaOH because of the greater yield . Some base catalysts that have been used in the Claisen-Schmidt reaction are KOH (yield 88-94%) , Ba(OH)2 (yield 88-98%) , NaOH (yield 90-96%) .
Is the major product formed in Claisen Schmidt reaction?
During the reaction a new carbon-carbon bond is formed; the product is a β-keto ester.
Which base is commonly used in Claisen condensation reaction?
The base of choice in Claisen condensation is the alkoxide ion corresponding to the alkoxy group in the ester.
What is the difference between aldol and Claisen condensation?
The key difference between aldol condensation and Claisen condensation is that aldol condensation describes the addition of enolates to aldehydes or ketones, whereas Claisen condensation describes the addition of enolates to esters.
Why is Claisen condensation reversible?
Because esters commonly contain both α-hydrogens and a carbonyl bond, they can undergo a reversible condensation similar to the aldol reaction called a Claisen Condensation.
What best describes the product of a Claisen condensation?
The product of a Claisen condensation is a beta-keto ester, which is a significantly stronger acid (pKa = 11) than either alcohols (pKa = 16-17) or esters (pKa = 25).
What is Claisen rearrangement reaction?
Crossed Aldol Condensation and Claisen-Schmidt …
Which of the following is used as a reagent is Schmidt rearrangement?
sulphuric acid to form amine directly.
Which reagent is used in Schmidt rearrangement?
Mechanism of the Schmidt Reaction
Alkenes are able to undergo addition of HN3 as with any HX reagent, and the resulting alkyl azide can rearrange to form an imine: Tertiary alcohols give substitution by azide via a carbenium ion, and the resulting alkyl azide can rearrange to form an imine.
What is Claisen rearrangement reaction?
Claisen rearrangement is an organic chemical reaction that offers a powerful method of the formation of carbon-carbon bonds. The reactant of this reaction – allyl vinyl ether, is converted into a gamma, delta-unsaturated carbonyl compound when subjected to heat or a Lewis acid.
What is Schmidt reaction which compound prepared by it?
The Schmidt reaction can be used to prepare benzanilide from benzophenone and hydrogen azide. This is an example of the preparation of an amide from a ketone and an azide.
What is called Wolff rearrangement?
The Wolff rearrangement, usually achieved through the decomposition of α-diazo carbonyl compounds, is a tool for the preparation of a wide variety of compounds. The ketenes formed through this method can be used in the preparation of β- and γ-lactams, cyclic ketones, or phenols just to name a few.
What type of bond is formed during elimination reaction?
During an elimination reaction, a bond forms by the removal of two atoms or groups from the original molecule. In most instances, the bond that forms is a π bond. Elimination reactions compete with substitution reactions when alkyl halides react with a nucleophile.