Date Published: August 01, 2009
Publisher: International Union of Crystallography
Author(s): Abdul-Basit Alhassan, Peter Norris, Matthias Zeller.
The title compound, C18H27N3O7, was synthesized by CuI-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 pyranose 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 molecules (A and B) with essentially identical conformations with a weighted r.m.s. deviation of only 0.09 Å. The molecules are arranged in layers with hydrophobic 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, intermolecular interactions 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 interact with each other via C—H⋯N hydrogen bonds which connect the molecules into two infinite chains of molecules made up of either A molecules or B molecules that stretch parallel to each other along . Between the butyl groups no directional interactions are observed.
For background information on N-glycosidic mimics of naturally occurring carbohydrates, see: Norris (2008 ▶); Temelkoff et al. (2006 ▶). For details of the synthesis of the carbohydrate starting material used, see: Zhang et al. (2007 ▶).