10138-10-0 4-03-00-01555 (Beilstein Handbook Reference) AI3-52376 BRN 1756021 Butanoic acid, 4-oxo-, ethyl ester Ethylester kyseliny 3-formylpropionove [Czech] Succinaldehydic acid, ethyl ester beta-Formyl propionic acid, ethyl ester