1-(2,3-Di-O-acetyl-4-chloro-4-de-oxy-6-O-tosyl-β-d-galactopyranos-yl)propan-2-one methanol 0.25-solvate.

The asymmetric unit of the title solvate, C(20)H(25)ClO(9)S·0.25CH(3)OH, contains one galactopyranosyl derivative and one-quarter of a methanol solvent mol-ecule. The galactopyran-ose ring is in the usual (4)C(1) conformation, and the anomeric center of the sugar has a β configuration. The value of θ (3.44°) and the range of torsion angles [or 53.1†(5)-63.0†(5)°] reflect a slight distortion of the (4)C(1) pyran-ose ring. A minor orientational disorder affects a carbonyl group, which was modeled with two sites for the O atom having occupancies of 0.79†(5) and 0.21†(5). The crystal studied exhibited inversion twinning.