Hydroxamate-directed access to β-Kdo glycosides

The reaction repertoire for forming transient aziridinone or azaoxyallyl cations from α-halohydroxamate is conceptually extended to design Kdo-glycosyl donors by installing the hydroxamate moiety at an anomeric centre, which is shown to be highly effective for stereoselective access to β-Kdo glycosides. The pivotal roles of hydroxamate over amide are revealed in control experiments. The manifold leading to aziridinone or azaoxyallyl cation, when incorporated at anomeric centre of Kdo-glycosyl donor, stereoselective glycosylation was achieved leading to β-Kdo glycosides. Pivotal roles of hydroxamate over amide is revealed in control experiments.