Enantiopure 2,3-dihydro-4-pyridones as synthetic intermediates: asymmetric synthesis of 1-deoxynojirimycin

An asymmetric synthesis of 1-deoxynojirimycin (2) mediated by a chiral auxiliary is reported. The dihydropyridone 4 was converted to diol 11 in three steps by acetoxylation, hydrolysis, and stereoselective reduction. Dihydroxylation of 11 followed by catalytic reduction afforded 2.