Stereospecific synthesis of chiral metabolites of ifosfamide and their determination in the urine

Abstract
The stereospecific synthesis of 2 chiral metabolites of ifosfamide (2) [an antitumor agent], 4-ketoifosfamide and 2-amino-3-(2-chloroethyl)tetrahydro-2H-1,3,2-oxazaphosphorine 2-oxide is reported. The absolute configuration of both compounds was assigned on the basis of chemical correlation. In addition, 2 other achiral metabolites of 2, carboxyifosfamide and IPAM [N,N''-bis(2-chloroethyl)phosphorodiamidic acid], were synthesized. These and other organophosphorus metabolites of ifosfamide were found, by 31P NMR, in the urine of patients to whom racemic 2 was administered. The measurements performed in the presence of an optically active lanthanide shift reagent showed considerable stereoselectivity of in vivo formation of some chiral metabolites of ifosfamide.