Concept:Aldol condensation is classified by its reaction mechanism, which involves a nucleophilic attack on a carbonyl carbon followed by loss of water.
Explanation:An aldehyde or ketone containing an
α-hydrogen forms an enolate in the presence of a base.
This enolate acts as a nucleophile and attacks the electrophilic carbonyl carbon of another carbonyl molecule.
This step is a nucleophilic addition to the carbonyl group.
The product formed is a
β-hydroxy carbonyl compound, commonly called an aldol.
On heating, the aldol undergoes dehydration, or elimination of a water molecule, to give an
α,β-unsaturated carbonyl compound.
Therefore, the overall mechanism is a nucleophilic addition step followed by an elimination step.
So the reaction is classified as a nucleophilic addition-elimination reaction.
It is not an electrophilic substitution, nucleophilic substitution, or electrophilic addition-elimination process.
Answer:Option D – Nucleophilic addition-elimination reaction.