N-(Methoxycarbonyl)-3-(methyl-d3)-L-valine-4,4,4,4',4',4'-d6 is an intermediate used in the synthesis of Atazanavir-d9 (A790053), which is the deuterated analog of Atazanavir (A790051), a azapeptide HIV protease inhibitor derivative. Atazanavir have been investigated as potential treatment of human immunodeficiency virus (HIV) and for anticancer purposes.