Methyl 3-O-α-l-fucopyranosyl β-d-glucopyran­oside tetra­hydrate

The title compound, C(13)H(24)O(10)·4H(2)O, is the methyl glycoside of a disaccharide structural element present in the backbone of the capsular polysaccharide from Klebsiella K1, which contains only three sugars and a substituent in the polysaccharide repeating unit. The conformation of the title disaccharide is described by the glycosidic torsion angles ϕ(H) = 51.1 (1)° and ψ(H) = 25.8 (1)°. In the crystal, a number of O—H⋯O hydrogen bonds link the methyl glycoside and water mol­ecules, forming a three-dimensional network. One water mol­ecule is disordered over two positions with occupancies of 0.748 (4) and 0.252 (4).