Transesterification

Transesterification is the process of exchanging the alkoxy group of an ester by another alcohol. These reactions are often catalyzed by the addition of an acid or base.

              O                       O
              ||                      ||
              C - CH3  +  ROH <--->   C - CH3  + CH3OH
             /                       /
         CH3O                      RO

  (ester  +  alcohol   <--->  different ester  +  different alcohol)

Transestrification is crucial for producing biodiesel from vegetable oils.