Provided herein are optically active compounds of the formulae:II; andIII and pharmaceutical compositions thereof. Also provided herein are processes of making these compounds and resolving the racemic mixture or the enrichment of same with in one of its enantiomers to provide (R)- and (S)-1-(3-(3-N,N-dimethylaminocarbonyl)phenoxyl-4-nitrophenyl)-1-ethyl-N,N’-bis(ethylene)phosphoramidate, and methods of treating cancer comprising administering such compounds.本文提供下式之光學活性化合物,II及III, 及其醫藥組合物。本文亦提供製造此等化合物及解析外消旋混合物或使其增濃其對映異構體之一以提供(R)-及(S)-1-(3-(3-N,N-二甲基胺基羰基)苯氧基-4-硝苯基)-1-乙基-N,N'-雙(伸乙基)胺基磷酸酯的方法,及包括投與此等化合物之治療癌症的方法。