Synthesis and structural characterization of the two epimeric O-cholesteryl-O-phenyl-N-phenylphosphoramidates

O-Cholesteryl-O-phenyl-N-phenylphosphoramidate was synthesized as intermedi ate for the stereoselective synthesis of organophosphates and phosphorothio ates. Single crystal X-ray diffraction discerned four independent P-epimeri c phosphoramidates cocrystallizing in the triclinic P1 space group. They we re found to be selectively paired in the crystal forming pseudo-centrosymme tric dimers via hydrogen bonds between the amide group of one epimer and th e phosphinoyl group of the other.