Question

Carry out the following conversion
Ethanal to But-2-enal

Hint:

Aldol condensation is used to form conjugated enals, and here, it is used to synthesize But-2-enal from Ethanal.

Answer 1

The conversion of Ethanal (Acetaldehyde) to But-2-enal involves an aldol condensation reaction. The steps are:
1. Aldol condensation: Ethanal undergoes aldol condensation in the presence of a base like NaOH to form But-3-en-2-al (crotonaldehyde). \[ \text{CH}_3\text{CHO} + \text{CH}_3\text{CHO} \xrightarrow{\text{NaOH}} \text{CH}_3\text{CH=CHCHO} \quad (\text{But-3-en-2-al}) \]
2. The final product is But-2-enal, which is the desired compound.