A complete asymmetric synthesis of polyhydroxypiperidines

A new general methodology for the asymmetric synthesis of polyhydroxypiperidines is described. The readily available achiral olefin 4 was transformed to 5-des(hydroxymethyl)-1-deoxynojirimycin (1) and its mannose analog 10 via regioselective aminohydroxylation (AA), ring-closing metathesis (RCM), and diastereoselective dihydroxylation reactions. Thus, the developed methodology made it possible to install all stereocenters in 1 and 10 in a highly stereocontrolled fashion.