Table of Contents
Beckmann Rearrangement
The Beckmann rearrangement is a chemical reaction in which a carbonyl group is transferred from an aldehyde or ketone to an amine, resulting in the formation of an imine. The reaction is named for the German chemist Felix Beckmann, who first described it in 1924.
Mechanism of Beckmann Rearrangement Reaction
The Beckmann Rearrangement is a reaction that converts a ketone into an aldehyde. The reaction catalyzed by an acid, and it occurs in two steps. The first step is the conversion of the ketone into an enolate ion. The second step is the conversion of the enolate ion into the aldehyde.
Beckmann Rearrangement Reaction Assisted by Cyanuric Chloride
The Beckmann Rearrangement Reaction is a type of organic reaction in which an aldehyde or ketone is converted into an alpha-hydroxy acid. The reaction assisted by the use of cyanuric chloride, which helps to stabilize the intermediate molecule and promote the reaction.
Beckmann Fragmentation
The Beckmann Fragmentation is a type of chemical reaction that cleaves a carbon-carbon bond in an organic molecule. Named for the German chemist Felix Beckmann, the reaction is a type of electrophilic aromatic substitution. The reaction typically occurs when an electron-rich aromatic molecule treated with a strong base, such as sodium hydroxide. The base removes an electron from the aromatic ring, creating a carbocation. The carbocation then reacts with a molecule of benzene, cleaving the carbon-carbon bond.
Applications of Beckmann Rearrangement Reaction
- The Beckmann rearrangement reaction is a powerful tool for the synthesis of chiral compounds from achiral precursors. The reaction is a rearrangement of an aldehyde or ketone to an enol, which can then reduced to the corresponding alcohol. The reaction named for the German chemist Max Beckmann, who first reported it in 1924.
- The Beckmann rearrangement is particularly useful for the synthesis of chiral alcohols. The enol intermediate can reduced to the corresponding alcohol with a chiral catalyst, such as a diastereomeric mixture of lithium aluminium hydride (LAH) or diisopropylzinc. The reduction can be stereoselective, giving rise to a chiral alcohol with the desired stereochemistry.
- The Beckmann rearrangement can also used to synthesize chiral ketones. The enol intermediate can converted to a chiral ketone with a chiral acid catalyst, such as (+)-mandelic acid. The ketone can then reduced to the corresponding alcohol with a chiral reducing agent, such as LAH or diisopropyl zinc.
- The Beckmann rearrangement also used in the synthesis of chiral amines. The enol intermediate can converted to a chiral amine with a chiral amine catalyst, such as (+)-N,N-dimethylglycine (DMG). The amine can then reduced to the corresponding alcohol with a chiral reducing agent, such as LAH or diisopropyl zinc.
