An Aldol-Based Approach to the Asymmetric Synthesis of l-Callipeltose, the Deoxyamino Sugar of l-Callipeltoside A

The l-callipeltose subunit of l-callipeltoside A has been synthesized in 10 steps and 13% overall yield from d-threonine. The key steps are a highly diastereoselective Felkin anti aldol addition to a methyl ketone and a selective methylation of a secondary alcohol in the presence of a secondary carbamate.