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The Buchner–Curtius–Schlotterbeck reaction is the reaction of aldehydes or ketones with aliphatic diazoalkanes to form homologated ketones. [1] It was first described by Eduard Buchner and Theodor Curtius in 1885 [ 2 ] and later by Fritz Schlotterbeck in 1907. [ 3 ]
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)
The Dakin oxidation (or Dakin reaction) is an organic redox reaction in which an ortho- or para-hydroxylated phenyl aldehyde (2-hydroxybenzaldehyde or 4-hydroxybenzaldehyde) or ketone reacts with hydrogen peroxide (H 2 O 2) in base to form a benzenediol and a carboxylate. Overall, the carbonyl group is oxidised, whereas the H 2 O 2 is reduced.
The usual electrophile is an aldehyde, since ketones are much less reactive. This is the 'enolate mechanism'. Despite the attractiveness of the aldol manifold, there are several problems that need to be addressed to render the process catalytic and effective. The first problem is a thermodynamic one: most aldol reactions are reversible.
In organic synthesis, it is a method to convert aldehydes and ketones into 1,3-hydroxyl compounds. The reaction sequence in many examples starts from conversion of a ketone into an enolate by action of lithium diisopropylamide (LDA), to which a suitable aldehyde is added.
The reaction was discovered by Teruaki Mukaiyama in 1973. [2] His choice of reactants allows for a crossed aldol reaction between an aldehyde and a ketone (>C=O), or a different aldehyde without self-condensation of the aldehyde. For this reason the reaction is used extensively in organic synthesis.
Reaction mechanism for the amine formation from a carboxylic acid via Schmidt reaction. In the reaction mechanism for the Schmidt reaction of ketones, the carbonyl group is activated by protonation for nucleophilic addition by the azide, forming azidohydrin 3, which loses water in an elimination reaction to diazoiminium 5.
Generally, a Mannich reaction is the combination of an amine, a ketone with a β-acidic proton and aldehyde to create a condensed product in a β-addition to the ketone. This occurs through an attack on the ketone with a suitable catalytic-amine unto its electron-starved carbon, from which an imine is created.