tert-Butyl 2-Methyl-3-oxobutanoate-D3 is a labelled analogue of tert-Butyl 2-Methyl-3-oxobutanoate. tert-Butyl 2-Methyl-3-oxobutanoate is used as a reagent to synthesize (+/-)-Methyl nonactate, an important starting material for the production of natural products.