Stereoselective synthesis of (3R,4S)-3-amino-4-methyl pyrrolidine

A stereoselective approach for the synthesis of (3R,4S)-3-amino-4-methyl pyrrolidine, a part of the structure of a quinoline antibacterial compound and the naphthyridine antitumor agent, is described. The key reaction is the one-pot reduction and regioselective cyclization of azidoditosyl derivative 9 to pyrrolidine 10.