De Novo Synthesis of the Bacterial 2-Amino-2,6-Dideoxy Sugar Building Blocks d-Fucosamine, d-Bacillosamine, and d-Xylo-6-deoxy-4-ketohexosamine

The cell-surface glycans on bacteria contain many monosaccharides that cannot be obtained by isolation from natural sources. Availability of differentially protected monosaccharides is therefore often limiting access to potential oligosaccharide vaccine antigens. d-Fucosamine, d-bacillosamine, and d-xylo-2,6-deoxy-4-ketohexosamine building blocks were prepared via a divergent de novo synthesis from l-Garner aldehyde. The route relies on a chelation-control assisted organometallic addition and an anti-selective dihydroxylation reaction.