The Perkin reaction is a type of aldol condensation of aromatic aldehydes and the anhydride of an aliphatic acid in the presence of sodium salt of the same acid, to give on heating an α,β-unsaturated acid.
Reaction mechanism
The carboxylate anion abstracts a proton from the a-carbon of the anhydride to form carbanion I.
This carbanion undergoes nucleophilic addition to carbonyl carbon of the aldehyde.
The anion II so formed takes up a proton to form a hydroxy compound III which first undergoes dehydration as an anhydride before it is hydrolyzed to the α,β-unsaturated acid.
Reaction mechanism
The carboxylate anion abstracts a proton from the a-carbon of the anhydride to form carbanion I.
This carbanion undergoes nucleophilic addition to carbonyl carbon of the aldehyde.
The anion II so formed takes up a proton to form a hydroxy compound III which first undergoes dehydration as an anhydride before it is hydrolyzed to the α,β-unsaturated acid.
