Chiral N-Moc-Pyrrolidine Bisphosphonate

摘要

We synthesized chiral ketophosphonate II and bis-phosphonates III and IV derived from the natural L-proline. Synthesis of compounds II-IV was carried out starting from Moc-protected L-proline (Moc = methoxy-carbonyl), which was converted into chloride I via reaction with dimethyliminium chloride. Amino acids chlorides were previously reported, but they were not individually isolated, and their physicochemical properties were not studied [1, 2]. Chloride I was isolated and purified by vacuum distillation without racemization as a colorless liquid stable in anhydrous conditions. The structure of compound I was proved by ~1H and ~(13)C NMR spectroscopy. The presence of the chlorine atom was confirmed by the elemental analysis data and by the reaction with triethyl phosphite.