The tetradeuterated analogues of (R)- and (S)-ifosfamide [(S)- and (R)-2-(2-chloro-2,2-dideuterioethyl)amino-3-(2-chloroethyl)-6,6-dideuterio-tetrahydro-2H-1,3,2-oxazaphosphorin-2-oxide, (S)- and (R)-1-d4] were synthesized by modification of a literature procedure. The enantiomers of α-methylbenzylamine were employed as the resolving agents in the multi-step synthesis in a 9% overall yield. The selected