Synthesis of the antibiotic 1,5‐dideoxy‐1,5‐imino‐D‐glucitol; concomitant formation of the D‐mannitol analogue

The easily accessible 1,2‐ O ‐isopropylidene‐3‐ O ‐benzyl‐α‐D‐glucofuranose was converted in six steps into 1,2‐ O ‐isopropylidene‐3,6‐di‐ O ‐benzyl‐5‐deoxy‐5‐azido‐α‐D‐glucofuranose. The latter afforded, after acidolysis followed by hydrogenolysis, 1‐deoxynojirimicine and a small quantity of 1‐deoxymannonojirimicine. The antibiotic thus obtained had an inhibitory effect on the trimming of N ‐linked carbohydrates in IgM.