A divergent approach to 3-azido-2,3,6-trideoxy-l-hexoses from rhamnal

An alternative strategy has been developed for producing 3-azido-2,3,6-trideoxy-l-hexoses, protected forms of daunosamine, ristosamine, acosamine, and epi-daunosamine. This method involved BF3·OEt2-induced peroxidation of rhamnal to construct key intermediate α,β-unsaturated lactone as the common precursor. After further derivatization, four 3-azido hexoses were successfully synthesized.