A norbornyl route to azasugars: stereoselective synthesis of isofagomine analogues

A stereoselective synthesis of new isofagomine analogues has been achieved from a suitably functionalized cyclopentene intermediate extracted from the norbornyl framework. Double reductive amination or inter- and intramolecular N-alkylations are the key steps in constructing the piperidine ring. Isofagomine derivatives exhibit moderate inhibitory activity in enzyme assays.