Absolute configuration of (-)-alpha-acetylmethadol hydrochloride

beta-[2-(Dimethylamino)propyl]-alpha-ethyl-beta-phenylbenzeneethanol+ ++ acetate ester hydrochloride, C23H32NO2+. Cl-.H2O, M(r) = 407.9, monoclinic, P2(1), a = 15.608 (4), b = 8.637 (2), c = 17.273 (5) A, beta = 97.71 (2) degrees, V = 2307.4 (1) A3, Z = 4 (two methadol hydrochlorides and two water molecules per asymmetric unit), Dx = 1.17 Mg m-3, lambda (Cu K alpha) = 1.54184 A, mu = 1.64 mm-1, F(000) = 880, T = 295 K, final R = 0.069, wR = 0.064 for 2559 independent observed reflections. Both asymmetric C atoms in the two independent methadol molecules are 'S'. Of the two N-H moieties one acts as a hydrogen-bond donor to a Cl atom (N-H = 1.21, H...Cl = 1.85, N...Cl = 3.03 A, N-H...Cl = 162.3 degrees) and the other is a donor to a water molecule (N-H = 0.90, H...O = 2.06, N...O = 2.80 A, N-H...O = 138.2 degrees). In addition, both water molecules hydrogen bond to both Cl atoms with O...Cl distances in the range 3.06-3.36 A. A comparison of torsion angles for the two independent methadol molecules indicates that there is very little stereochemical similarity between them.