Methyl 4-O-β-l-fucopyranosyl α-­d-­glucopyranoside hemihydrate

The crystal structure of methyl 4-O-β-l-fuco­pyran­osyl α-d-gluco­pyran­oside hemihydrate C₁₃H₂₄O₁₀·0.5H₂O is organized in sheets with antiparallel strands, where hydro­phobic interaction accounts for partial stabilization. Infinite hydrogen-bonding networks are observed within each layer as well as between layers; some of these hydrogen bonds are mediated by water mol­ecules. The conformation of the disaccharide is described by the glycosidic torsion angles: ϕ_H = −6.1° and ψ_H = 34.3°. The global energy minimum conformation as calculated by molecular mechanics in vacuo has ϕ_H = −58° and ψ_H = −20°. Thus, quite substantial changes are observed between the in vacuo structure and the crystal structure with its infinite hydrogen-bonding networks.