An Enantioselective Synthesis of Deoxynojirimycin

An intramolecular nitrone cycloaddition of the N-alkenylnitrone 2 is the key piperidine ring forming reaction in a novel twelve-step synthesis of deoxynojirimycin (1). The highly regioselective elimination of H2O from the secondary alcohol 3 with the Martin sulfurane afforded alkene 4. Ozonolysis and reduction of the ozonide with DIBAL-H were used for the controlled introduction of the required equatorial substituent.