Tishchenko reaction

Tishchenko Reaction

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Schematic representation of the Tishchenko reaction.

The Tishchenko reaction is an organic chemical reaction that involves the disproportionation of an aldehyde in the presence of an alkoxide to form an ester. This reaction is named after the Russian chemist Vyacheslav Tishchenko, who discovered it in 1906.

Mechanism

The Tishchenko reaction proceeds through a mechanism that involves the formation of a hemiacetal intermediate. The reaction typically requires an aluminum alkoxide as a catalyst. The general mechanism is as follows:

1. The aldehyde undergoes nucleophilic attack by the alkoxide ion, forming a hemiacetal.
2. The hemiacetal then undergoes a rearrangement, transferring a hydride ion to another molecule of the aldehyde, resulting in the formation of an ester and an alcohol.

This reaction is particularly useful for the synthesis of esters from aldehydes without the need for an external oxidizing agent.

Applications

The Tishchenko reaction is used in the industrial synthesis of esters, which are valuable as solvents, plasticizers, and precursors to various chemical compounds. It is also employed in the synthesis of natural products and pharmaceuticals.

Related Reactions

The Tishchenko reaction is related to other reactions involving aldehydes and alcohols, such as the Cannizzaro reaction, which also involves the disproportionation of aldehydes but results in the formation of an alcohol and a carboxylic acid instead of an ester.

See Also

• Aldol reaction
• Cannizzaro reaction
• Esterification
• Hydride transfer

Related Pages

• Vyacheslav Tishchenko
• Organic chemistry
• Catalysis