Diethyl 2-methyl-3-oxobutane-1,4-dioateDiethyl 2-methyl-3-oxosuccinateDiethyl oxalpropionateDiethyl 2-methyl-3-oxosuccinateNSC 33946草酰丙酸二乙酯Methyloxo-butanedioic acid diethyl esterDiethyl oxalpropionateDiethyl oxalpropionateDiethyl 3-methyl-2-oxosuccinateEthyl alpha-ethoxalylpropionatediethyl 2-methyl-3-oxosuccinateDiethyl 2-methyloxosuccinateDiethyl methyloxobutanedioatediethyl 2-methyl-3-oxosuccinateDiethyl 2-methyl-3-oxosuccinate