Asymmetric Dihydroxylation of d-Glucose Derived α,β-Unsaturated Ester:  Synthesis of Azepane and Nojirimycin Analogues

The asymmetric dihydroxylation of a d-glucose derived α,β-unsaturated ester 3 afforded syn vicinal diols in good to high diastereoselectivity. The conversion of these vicinal diols to the corresponding cyclic sulfate, regio-, stereoselective nucleophilic ring opening by sodium azide, and LAH reduction afforded amino heptitols 7a,b that were converted to azepane 1c,d and nojirimycin analogues 2c,d.