Expeditious synthesis of bacterial, rare sugar building blocks to access the prokaryotic glycome.

Bacteria have unusual glycans which are not accessible by isolation. Herein, we describe a general and divergent strategy for the synthesis of the rare, bacterial deoxy amino hexopyranoside building blocks from d-mannose. The methodology is applied to the first total synthesis of the l-serine linked trisaccharide of Neisseria meningitidis.