3-[(2-methylpropan-2-yl)oxy]-3-oxopropanoic acid; Propanedioic acid, 1-(1,1-dimethylethyl) ester; 3-[(2-Methylpropan-2-yl)oxy]-3-oxopropanoic acid; Malonic acid mono-tert-butyl ester; tert-Butyl hydrogen malonate