esterhydrolyse

Esterhydrolyse, or ester hydrolysis, is the chemical process in which an ester reacts with water to yield a carboxylic acid (or carboxylate) and an alcohol. The reaction proceeds by two main routes: acidic hydrolysis and base-catalyzed hydrolysis (saponification). In acidic hydrolysis, a mineral acid such as sulfuric acid or hydrochloric acid protonates the carbonyl oxygen, increasing its susceptibility to nucleophilic attack by water. A tetrahedral intermediate forms, followed by proton transfers and departure of the alkoxy leaving group, yielding a carboxylic acid after deprotonation. The process is equilibrium-controlled and is often driven to completion by heating and removal of one product.

Base-catalyzed hydrolysis proceeds via nucleophilic attack of hydroxide on the carbonyl carbon. The tetrahedral intermediate collapses to give a carboxylate salt and an alcohol. This pathway is typically irreversible under aqueous workups because the carboxylate salt is stable in basic conditions; neutralization or acidification can regenerate the free carboxylic acid.

Enzymatic hydrolysis is carried out by esterases and lipases in biological systems, essential in digestion and metabolism. The rate and outcome depend on the ester structure, the leaving group ability, pH, and temperature.

Applications include converting esters to acids or salts in organic synthesis, degrading polyesters, and processing fats and oils in biology and industry. Safety considerations relate to the handling of strong acids or bases and the potential odor or toxicity of certain esters.