(i) Acetylation : Introduction of acetyl group
in alcohols, phenols or amines is called their acetylation.
(ii) Aldol condensation : Two molecules of an aldehyde or ketones having at least one α-hydrogen atom condense in the presence of a dilute alkali to give β-hydroxyaldehyde or β-hydroxyketone which upon heating give α,β-unsaturated aldehyde or ketone.
