(2R,3S)-2-Ammonio-3-hydr-oxy-3-(4-nitro-phen-yl)propanoic acid chloride monohydrate.

The title compound, C(9)H(11)N(2)O(5) (+)·Cl(-)·H(2)O, was synthesized from (1S,2S)-2-amino-1-(4-nitro-phen-yl)propane-1,3-diol in four steps. As demonstrated by this work, no racemization occurs during this synthetic procedure. The crystal structure displays many inter-molecular hydrogen bonds between the acidic cation, chloride anions and the water mol-ecules, forming a three-dimensional network. An intra-molecular bond between the ammonium group and a hydroxyl O atom is also present.