2,5-Dihydro-5-oxofuran-2-acetate 2-Oxo-2,5-dihydrofuran-5-acetate 4-Carboxymethyl-4-hydroxyisocrotonolactone 5-Oxo-2,5-dihydrofuran-2-acetate 6666-46-2 C04105 Muconolactone