Efficient and stereodivergent synthesis of deoxyimino sugars

Both cis - and trans -2-substituted-1,2,3,6-tetrahydro-pyridin-3-ols have been prepared via an aldol condensation–ring-closing metathesis sequence. A stereodivergent synthesis of optionally functionalized deoxyimino sugars was achieved via asymmetric dihydroxylation or epoxidation/nucleophilic substitution of these tetrahydropyridines.