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The carboxylic acid Schmidt reaction starts with acylium ion 1 obtained from protonation and loss of water. Reaction with hydrazoic acid forms the protonated azido ketone 2 , which goes through a rearrangement reaction with the alkyl group R, migrating over the C-N bond with expulsion of nitrogen.
The aldol reaction (aldol addition) is a reaction in organic chemistry that combines two carbonyl compounds (e.g. aldehydes or ketones) to form a new β-hydroxy carbonyl compound. Its simplest form might involve the nucleophilic addition of an enolized ketone to another:
For these latter reactions, two equivalents of the incoming group add to form an alcohol rather than a ketone or aldehyde. This occurs even if the equivalents of nucleophile are closely controlled. Overaddition of nucleophiles. The Weinreb–Nahm amide has since been adopted into regular use by organic chemists as a dependable method for the ...
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to give a conjugated enone. The overall reaction equation is as follows (where the Rs can be H)
Fig. 1: Mechanism of an intramolecular aldol reaction in basic conditions. Aldol addition product; bottom right Aldol condensation product; top right. Intramolecular aldol condensation is between two aldehyde groups or ketone groups in the same molecule. Five- or six-membered α, β-unsaturated ketone or aldehydes are formed as products. This ...
The Leuckart reaction is the chemical reaction that converts aldehydes or ketones to amines. The reaction is an example of reductive amination. [1] The reaction, named after Rudolf Leuckart, uses either ammonium formate or formamide as the nitrogen donor and reducing agent. It requires high temperatures, usually between 120 and 130 °C; for the ...
Below, the reaction mechanism is shown with R 2 = H: Mukaiyama Aldol-MechanismusV7 en. In the cited example the Lewis acid TiCl 4 is used. First, the Lewis acid activates the aldehyde component followed by carbon-carbon bond formation between the enol silane and the activated aldehyde. With the loss of a chlorosilane the compound 1 is built.
The Gewald reaction (or the Gewald aminothiophene synthesis) is an organic reaction involving the condensation of a ketone (or aldehyde when R 2 = H) with a α-cyanoester in the presence of elemental sulfur and base to give a poly-substituted 2-amino-thiophene. [1] [2] The Gewald reaction. The reaction is named after the German chemist Karl ...