Synthesis of 1,2-cis-Homoiminosugars Derived from GIcNAc and GaINAc Exploiting a β-Amino Alcohol Skeletal Rearrangement

The synthesis of 1,2-cis-homoiminosugars bearing an NHAc group at the C-2 position is described. The key step to prepare these a-d-GlcNAc and a-d-GalNAc mimics utilizes a beta-amino alcohol skeletal rearrangement applied to an azepane precursor. This strategy also allows access to naturally occurring a-HGJ and a-HNJ. The a-d-GlcNAc-configured iminosugar was coupled to a glucoside acceptor to yield a novel pseudodisaccharide. Preliminary glycosidase inhibition evaluation indicates that the a-d-GalNAc-configured homoiminosugar is a potent and selective a-N-acetylgalactosaminidase inhibitor.