Acetaldehyde when treated with dilute NaOH gives
CH3−CH|OH−CH2−CHO
Aldol condensation occurs in aldehydes having α-hydrogen with a dilute base to give β-hydroxy aldehydes called aldols. This reaction is most commonly known as aldol condensation. If the condensation reaction occurs between two different carbonyl compounds it is called crossed aldol condensation.
Aldol Condensation can be defined as an organic reaction in which enolate ion reacts with a carbonyl compound to form β-hydroxy ketone or β-hydroxy aldehyde, followed by dehydration to give a conjugated enone. Aldol Condensation plays a vital role in organic synthesis, creating a path to form carbon-carbon bonds.
The reaction is as follows:
2CH3CHOdil−−−−→NaOHCH3−OH|CH−CH2CHO
Mechanism involves 3 steps:
1) Enolate formation
2) Addition of the enolate
3) Formation of an aldol