Dear Walid,

Malonic anhydride or oxetane-2,4-dione is an organic compound with chemical formula C₃H₂O₃ or CH₂(CO)₂O. It can be viewed as the anhydride of malonic acid, or a double ketone of oxetane. It is a four-membered ring moiety.

Maleic anhydride is an organic compound with the formula C₂H₂(CO)₂O. It is the acid anhydride of maleic acid. It is a five-membered ring moiety.

It is expected that both anhydrides undergo hydrolysis, however, the hydrolysis rate of malonic anhydride is much higher than that of maleic anhydride due to the fact that malonic anhydride has a more strained ring (4-membered ring) than that of maleic anhydride (5-membered ring).

Hoping this will be helpful,

Rafik

thanx dr