A new stereoselective synthesis of both (2R, 4R)-and (2S, 4S)-4-hydroxy-proline and (+)- and (−)-bulgecinine was performed starting from synthons 1 or 1′, respectively. The synthetic route has been established via a novel assisted cleavage of a disubstituted amide in mild conditions and successive stereocontrolled iodocyclization (Schemes 1 and 2).
