The enediol I1 is a black to dark purple crystalline solid with a metallic luster, mp 232- 233'(dec.). The stability is such that there is no appreciable change in appearance or melting point after six months storage at room temperature. It affects Tollens reagent, is oxidized by sodium 2, 6-dichlorobenzeneoneindophenol, forms a dibenzoate, mp 236", and in bubbling air through a dioxane solution gives a faintly yellow benzil (IV), mp 271-272", in ...