Stereoselective Synthesis of (+)-Polyoxamic Acid Starting with a Chiral Aziridine

An efficient and stereoselective synthesis of (+)-polyoxamic acid was developed. The route starts with the commercially available 1-(R)--methylbenzylaziridine-2-methanol, a substance that has not been used previously as a starting material for the preparation of this target. The route also features the use of a stereocontrolled Sharpless asymmetric dihydroxylation reaction, promoted by AD-mix-, which is followed by a regioselective aziridine ring-opening process, to generate the basic skeleton of target natural product. Subsequent oxidation and global deprotection produces (+)-polyoxamic acid.