Which of the following compound would undergo Aldol condensation?

Explanation:

→ Methanal (formaldehyde) cannot undergo Aldol condensation because it has only one carbon atom and does not have an alpha hydrogen atom.

→ Benzaldehyde has an alpha hydrogen atom and can undergo Aldol condensation, but it forms a mixture of products due to the presence of two carbonyl groups that can react.

2,2-Dimethylbutanal does not have an alpha hydrogen atom and cannot undergo Aldol condensation.

→ Phenylacetaldehyde has an alpha hydrogen atom and can undergo Aldol condensation to form an alpha-beta unsaturated aldehyde.

→ Aldol condensation is a reaction between two molecules of aldehydes or ketones that contain alpha hydrogen atoms. The alpha hydrogen atom undergoes deprotonation to form an enolate ion, which then reacts with another molecule of aldehyde or ketone to form a beta-hydroxy aldehyde or ketone. The product undergoes dehydration to form an alpha-beta unsaturated aldehyde or ketone.

→ Therefore, only Phenylacetaldehyde can undergo Aldol condensation among the given options.

Aldehydes which contain at least 2α hydrogen atoms, undergo Aldol condensation reaction Phenylacetaldehyde contains 2α hydrogen atoms and undergoes Aldol condensation reaction in presence of dilute alkali.