Synthesis of methyl α-l-callipeltoside

The synthesis of callipeltose, a novel amino sugar with the proposed structure, 4-amino-4,6-dideoxy-2,O-3-C-dimethyl-l-talopyranosyl-3,4-urethane, from l-rhamnose is described. Oxime reduction, carbamate cyclization and selective methylation are key steps. The synthesis supports the assignment of the relative stereochemistry of callipeltose.