What is aldol condensation reaction?

Aldol condensation reaction

• "Aldehydes and ketones having at least one $\mathrm{\alpha }$-hydrogen undergo a reaction in the presence of dilute alkali as a catalyst to form β-hydroxy aldehydes (aldol) or $\mathrm{\beta }$-hydroxy ketones (ketol), respectively. This is known as Aldol reaction."
• $\mathrm{\alpha }$-hydrogen is necessary for aldol condensation reaction.

Chemical reaction

• Aldol condensation of ethanol is as follows

• The mechanism for aldol condensation of ethanol is as follows