Microscale Claisen adapter/head often used to facilitate syringe addition of reagents to sealed or moisture-sensitive systems. With inner joint at bottom and two outer joints externally threaded for an O-RING-CAP-SEAL connection with mating male joints.
What is the function of Claisen adapter?
The Claisen adaptor is a multi-purpose item of standard taper glassware. It is used in situations which require more than one outlet from a round-bottom flask. For instance, in a reflux of a reaction mixture, sometimes it is necessary to condense the rising vapors and add reactants to the mixture at the same time.
What type of reaction is Claisen?
The Claisen condensation reaction is an organic coupling reaction that results in the formation of a C-C bond between either a single ester and one carbonyl compound or between two esters. The reaction proceeds when a strong base is present and the product of the reaction is a beta-keto ester or a beta-diketone.
Why is Claisen condensation important?
The Claisen condensation – strictly the condensation of two esters with the concomitant release of one of the constituent alcohol moieties – is arguably the most important carbon–carbon bond-forming reaction in biology, as it is used in the biosynthesis of fatty acids, polyketides, and a large variety of other
What is a Claisen head? – Related Questions
Why is it called Claisen condensation?
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.
Which takes place in Claisen 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.
Which base is commonly used in Claisen condensation reaction?
In mixed Claisen condensations, a non-nucleophilic base such as lithium diisopropylamide, or LDA, may be used, since only one compound is enolizable.
What is the mechanism of Claisen rearrangement?
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.
Why is the Claisen Schmidt reaction important?
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].
What are the reagents used in Claisen rearrangement?
The Ireland–Claisen rearrangement is the reaction of an allylic carboxylate with a strong base (such as lithium diisopropylamide) to give a γ,δ-unsaturated carboxylic acid.
What is the driving force of the Claisen reaction?
The Claisen Condensation between esters containing α-hydrogens, promoted by a base such as sodium ethoxide, affords β-ketoesters. The driving force is the formation of the stabilized anion of the β-keto ester.
Why is it called Claisen condensation?
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.
Is Claisen 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.
Which base is commonly used in Claisen condensation reaction?
In mixed Claisen condensations, a non-nucleophilic base such as lithium diisopropylamide, or LDA, may be used, since only one compound is enolizable.
What is the nucleophile in Claisen condensation?
In the Claisen condensation the nucleophile is the ROC(O)CH2 group which displaces (RO-). Alkoxides can be adequate leaving groups in this case, since they’re significantly weaker bases than ester enolates.
What enzyme catalyzes a Claisen condensation?
Citrate synthase catalyzes the Claisen condensation between acetyl CoA and oxaloacetate to yield, after hydrolysis of the thioester bond, citrate and CoA.
Which carbon carbon bond is formed in the Claisen reaction?
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.
| Claisen condensation |
| RSC ontology ID |
RXNO:0000043 |
Why is CC bond activation important?
Activating them for useful chemical transformation is one of the newest and biggest challenges in organic synthesis. Efficient C-C bond activation would contribute not only to atom economy but also to the development of novel synthetic strategies and the discovery of unknown compounds.
How CC bonds are formed?
Usually, carbon-carbon bonds are formed by coupling two carbons each of which are already functionalized in some way, as with the displacement of a C-Br with NaCN to form C–CN. It would be more efficient, and potentially less expensive and less polluting, if one of the partners could be an ordinary C-H bond.
What is the difference between aldol and Claisen?
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.