Succinic anhydride

CAS 108-30-5

Succinic anhydride (CAS 108-30-5) illustrates how molecular structure determines chemical role. Succinic anhydride is the cyclic anhydride of succinic acid, a compact five-membered ring whose two carbonyl groups make it an efficient acylating and succinylating reagent. Water opens the ring to regenerate succinic acid, while alcohols and amines produce succinate esters and amides. This controlled ring opening makes succinic anhydride useful in organic synthesis, polymer modification, surface functionalization, and preparation of pharmaceutical and specialty-chemical intermediates. Its story is a classic example of activation by dehydration: converting a dicarboxylic acid into a cyclic anhydride stores reactivity in the ring, allowing nucleophiles to introduce a four-carbon succinyl spacer under comparatively straightforward conditions. Its exact chemical identity remains important when distinguishing related forms and applications.