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Idealized scheme showing condensation of two amino acids to give a peptide bond. Many variations of condensation reactions exist. Common examples include the aldol condensation and the Knoevenagel condensation , which both form water as a by-product, as well as the Claisen condensation and the Dieckman condensation (intramolecular Claisen ...
Acid–base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules ...
Occasionally, an aldol condensation is buried in a multistep reaction or in catalytic cycle as in the following example: [18] Ru Catalyzed Cyclization of Terminal Alkynals to Cycloalkenes. In this reaction an alkynal 1 is converted into a cycloalkene 7 with a ruthenium catalyst and the actual condensation takes place with intermediate 3 through 5.
Peptide bond formation via dehydration reaction. When two amino acids form a dipeptide through a peptide bond, [1] it is a type of condensation reaction. [2] In this kind of condensation, two amino acids approach each other, with the non-side chain (C1) carboxylic acid moiety of one coming near the non-side chain (N2) amino moiety of the other.
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle . [ 1 ] It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within ...
One important class of condensation polymers are polyamides. [4] They arise from the reaction of carboxylic acid and an amine. Examples include nylons and proteins. When prepared from amino-carboxylic acids, e.g. amino acids, the stoichiometry of the polymerization includes co-formation of water: n H 2 N-X-CO 2 H → [HN-X-C(O)] n + (n-1) H 2 O
It is a modification of the aldol condensation. [1] [2] A Knoevenagel condensation is a nucleophilic addition of an active hydrogen compound to a carbonyl group followed by a dehydration reaction in which a molecule of water is eliminated (hence condensation). The product is often an α,β-unsaturated ketone (a conjugated enone).
This reaction sequence is thus a condensation reaction since there is a net loss of HCl when the two reactant molecules join. [7] Arrow-pushing mechanism for the Darzens reaction. If the starting halide is an α-halo amide, the product is an α,β-epoxy amide. [8] If an α-halo ketone is used, the product is an α,β-epoxy ketone. [2]