Stereocontrolled transformation of nitrohexofuranoses into cyclopentylamines via 2-oxabicyclo[2.2.1]heptanes: incorporation of polyhydroxylated carbocyclic beta-amino acids into peptides.

A promising new strategy for the transformation of nitrohexofuranoses into cyclopentylamines, based on intramolecular cyclization followed by controlled opening of the resulting 2-oxabicyclo[2.2.1]heptane derivatives, allowed the first total synthesis of a carbocyclic beta-amino acid and its incorporation into peptides. This strategy also afforded a new route to cyclopentylamines with well-known glycosidase inhibition properties. [reaction: see text]