ANHYDRIDE THEORY

Anhydrides come from condensing two molecules of carboxylic acids. The condensation of two molecules of the same acid gives rise to symmetrical anhydrides, which are named by replacing the word acid with anhydride .

anhydride nomenclature1

[1] Ethanoic anhydride

[2] Propanoic anhydride

[3] Benzoic anhydride

Anhydrides react with water to give carboxylic acids. The reaction can be carried out without acid catalysis, under slight heating.

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Anhydrides react with alcohols to form esters. The reaction can be carried out without acid catalysis, under slight heating.

 
anhidridos-reaccion-alcoholes

The anhydrides react with amines and ammonia to form amides. Under the reaction conditions, a carboxylic acid is also obtained.

 
anhidridos-reaccion-aminas

Lithium aluminum hydride reduces the anhydrides to alcohols. In a first stage the molecule breaks, forming aldehyde and carboxylate which are in turn reduced to alcohols.

 
reduccion-anhidridos