Question

Tischenko reaction is a modification of :

• A. Aldol condensation
• B. Claisen condensation
• C. Cannizzaro reaction
• D. Pinacol-pinacolon reaction

Answer 1

The Correct Option is C

The Tischenko reaction is a specific biochemical reaction in organic chemistry. It involves the transformation of aldehydes into esters using an aluminum alkoxide catalyst. This reaction is considered a modification of the Cannizzaro reaction.

Explanation:

• The Cannizzaro reaction is a chemical reaction where two molecules of a non-enolizable aldehyde are reacted to produce one molecule of alcohol and one molecule of the corresponding carboxylate salt under basic conditions.
• The Tischenko reaction is a variant where, instead of producing an alcohol and a carboxylate, a disproportionation happens in the presence of aluminum alkoxide, leading to the formation of an ester.

Why the other options are incorrect:

• Aldol condensation involves enolizable aldehydes or ketones and results in the formation of β-hydroxy aldehydes or ketones, which can further dehydrate to give α,β-unsaturated carbonyl compounds.
• Claisen condensation involves the acylation of an ester with an enolate ion, forming a β-keto ester.
• Pinacol-pinacolon rearrangement involves the rearrangement of a vicinal diol (pinacol) into a ketone (pinacolone) via acid-catalyzed dehydration.

Thus, the correct answer is that the Tischenko reaction is a modification of the Cannizzaro reaction.