(R)-(-)-4-Benzyl-3-propionyl-2-oxazolidinone-D3 is an intermediate in the synthesis of (S)-3-Hydroxy-2-methylpropanoic Acid-d3 sodium salt (H997291), which is the labelled version of 3-hydroxy-2-methyl-Propanoic acid sodium salt (CAS# 1893416-17-5), a useful building block used in the synthesis of aminotriazine derivatives.