“ Aqueous solutions of the acid are decomposed in sunlight by uranium salts, with evolution of carbon dioxide and the formation of propionic acid. Potassium permanganate, in acid solution, oxidizes it to carbon dioxide and water. The sodium salt on distillation with phosphorus trisulphide gives thiophene. The esters of the acid condense readily with aromatic aldehydes and ketones to form γ-disubstituted itaconic acids and γ-alkylen pyrotartaric acids (H. Stobbe, Ann, 1899, 308, p. 71) . γ-Oxyacids are formed when aldehydes are heated with sodium succinate and sodium acetate. ”

“ It is also produced by the electrolysis of a concentrated solution of potassium ethyl malonate.
It crystallizes in prisms or plates which melt at 185° C. and boil at 235° C. with partial conversion into the anhydride. It is readily soluble in water. ”