Expeditious Synthesis of a Common Intermediate of l -1-Deoxyallonojirimycin and l -1-Deoxymannojirimycin

The expeditious synthesis of a common intermediate of L-1-deoxyallonojirimycin (L-allo-DNJ) and L-1-deoxymannojirimycin (L-manno-DNJ) is reported. This intermediate is obtained in highly diastereo- and enantioselectivity with 38.4% overall yield in six steps involving the unprecedented ring-closing metathesis of a tert-butylsulfinyl allylamine as the key step.