1,2-Oxathiolan-5-one, 2,2-dioxide 3-Sulfopropionic acid cyclic anhydride 3-Sulfopropionic anhydride 5961-88-6 NSC 66415 Propanoic acid, 3-sulfo-, cyclic anhydride Propionic acid, 3-sulfo-, cyclic anhydride Sulfopropanoic anhydride Sulfopropionic acid anhydride Sulfopropionic anhydride