Certain dicarboxylic acids spontaneously eliminate water when heated forming cycioc anhydirides. But for the reaction to be successfully. The cyclic anhydrides product must normally have a ring size of fivee or six members. There are two important reasons, first, the second carboxyl group can serve as the acid catalyst (by intramolecular proton transfer), as well as the nucleophile. And second, the high temperature involved reduce the need for catalyst.

Which of the following dicarboxylic acid would you expect to form cyclic anhydride?

Options

A.
B.
C.
D.

Answer

C