Dimethyl (±)-(1S*,2R*,3S*)-[3-phenyl-1-(N-phenylcarbamoyloxy)-2, 3-epoxypropyl]-phosphonate

The crystal structure of the racemic title compound, C₁₈H₂₀NO₆P (m.p. 428-431 K), has been determined by X-ray diffraction. The title compound consists of a tetrahedral P atom bonded to two methoxy groups, and an alkyl chain. The alkyl chain is substituted at position 1 with a carbamate and with an epoxide at positions 2 and 3. The relative configuration of the 1-carbamate and 2,3-epoxide substituents was confirmed as anti (1S,2R,3S). The crystal structure contains an enantiomeric pair with two intermolecular hydrogen bonds in a 14-membered ring. The hydrogen bonds are formed between the P=O of one enantiomer and the N-H of the other.