2-Phenylethyl 1-thio-β-dgalactopyranoside hemihydrate

Abstract

The title compound, C 14H 20O 5S·0. 5H 2O, crystallizes with two organic molecules and a solvent water molecule in the asymmetric unit. In both molecules, the hexapyranosyl rings adopt a slightly distorted chair conformation ( 5 C 2) with four substituents in equatorial positions and one substituent in an axial position. The main difference between the organic molecules is the dihedral angle between the phenyl ring and the best plane defined by the O - C1 - C2 - C3 atoms (r.m.s deviations = 0.003 and 0.043 Å) of the hexapyranosyl rings [47.4 (4) and 86.5 (4)°]. In the asymmetric unit, molecules are linked by two strong O - H⋯O hydrogen bonds. In the crystal, the components are linked by a total of 10 distinct O - H⋯O hydrogen bonds, resulting in the formation of a twodimensional network parallel to the ab plane.