4-Butyl-1-(2,3,4-tri-O-acetyl-β-l-fuco-pyranos-yl)-1H-1,2,3-triazole

The title compound, C(18)H(27)N(3)O(7), was synthesized by Cu(I)-catalysed coupling of an azide with an alkyne as part of a study into the synthesis of N-glycosyl-1,2,3-triazoles. The crystal structure confirms the selective formation of the β-conformer of the pyran-ose N-glycoside, thus confirming the retention of stereochemistry during heterocycle formation with the N-glycosyl triazole group occupying the equatorial position at the anomeric C atom. The structure exhibits two crystallographically independent mol-ecules (A and B) with essentially identical conformations with a weighted r.m.s. deviation of only 0.09 Å. The mol-ecules are arranged in layers with hydro-phobic and more polar sections built from the butyl triazole units on the one hand and the more polar moieties dominated by the carbohydrate units on the other. Within the polar layers, inter-molecular inter-actions are dominated by a three-dimensional network of weak C-H⋯O hydrogen bonds with the acetyl keto O atoms as the hydrogen-bond acceptors. The triazole units inter-act with each other via C-H⋯N hydrogen bonds which connect the mol-ecules into two infinite chains of mol-ecules made up of either A mol-ecules or B mol-ecules that stretch parallel to each other along [100]. Between the butyl groups no directional inter-actions are observed.