👉 In organic chemistry, a diester is an ester that has two or more carbon atoms bonded to one or both of the carbons. The term "diester" refers to a single bond between the two carbon atoms in a diester. In the context of esters, diesters are often used as esters with higher degrees of unsaturation. For example, in the ester formation reaction between ethylamine (C2H5Cl) and propionate (C4H