Hydrolytic reactions of organic acid derivatives

The reactivity of organic acid derivatives in nucleophile reactions decreases in the following order  

Acid halides acid anhydrides acid esters. 

The most reactive of halides of acids are iodides, in the case of esters the most reactive are gener y methylesters of carboxylic acids. The most important transformations of carboxylic acids and their derivatives include esterification and hydrolysis of esters and amides. Esters and amides are hydrolysed in both acid and alkaline media. 

The acid hydrolysis of esters and esterification are mutually reversible processes, and, therefore, they take place by the same mechanism in the direction  

Alkaline hydrolysis of esters by the mechanism takes place in the following way  

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