Enantiopure compound (2R,3R,5S)-3,5-dimethyl-2-(3-chlorophenyl)-2-morpholinol hydrochloride (4a) was synthesized from (S)-2-amino-1-propanol and 2-bromo-m-chloropropiophenone, and (2S,3S,5R)-3,5- di-methyl-2-(6-methoxy-2-naphthyl)-2-morpholinol hydrochloride (4b) was from the enantioisomer (R)-2- amino-1-propanol and 6-methoxy-2-(2-bromopropionyl)naphthalene. Their crystal structures and absolute configurations were determinated by X-ray diffraction experiment and their stereo-structures were tentatively discussed. The compound 4a crystal belongs to orthorhombic system with space group P2₁2₁2 and cell parameters: a＝0.8718(2) nm, b＝0.7883(2) nm, c＝2.0247(6) nm, Z＝4, V＝1.3915(7) nm³, D_c＝1.328 g/cm³, F(000)＝584, R₁＝0.0399, wR₂＝0.0797, S＝1.042. The compound 4b crystal belongs to ortho-rhombic system with space group P2₁2₁2₁ and cell parame-ters: a＝0.71035 (9) nm, b＝0.77703(10) nm, c＝2.9820(4) nm, Z＝4, V＝1.6318(4) nm³, D_c＝1.318 g/cm³, F(000)＝688, R₁＝0.0520, wR₂＝0.1108, S＝0.994.

Key words: chiral, crystal structure, (R)-2-amino-1-propanol, synthesis, morpholinol, (S)-2-amino-1-propanol