OPTICAL RESOLUTION BY PREFERENTIAL CRYSTALLIZATION OF (2RS,3SR)-2-AMINO-3-CHLOROBUTANOIC ACID HYDROCHLORIDE

(2RS,3SR)-2-Amino-3-chlorobutanoic acid hydrochloride [(2RS,3SR)-ACB.H Cl] was found to exist as a conglomerate based on the melting point, i nfrared spectrum, and solubility. Optical resolution by preferential c rystallization of (2RS,3SR)-ACB.HCl was achieved to yield both (2R,3S) - and (2S,3R)-ACB.HC1 of 80-100% optical purities. The obtained (2R,3S )- and (2S,3R)-ACB.HCl were recrystallized, taking into account the so lubility of (2RS,3SR)-ACB.HCl, to give efficiently optically pure (2R, 3S)- and (2S,3R)-ACB.HCl. Treatment of the purified (2R,3S)- and (2S,3 R)-ACB.HCl with triethylamine gave optically pure (2R,3S)- and (2S,3S) -2-amino-3-chlorobutanoic acid, respectively. (C) 1997 Wiley-Liss, Inc .