A new and expeditious asymmetric synthesis of (R)- and (S)-2-aminoalkanesulfonic acids from chiral amino alcohols

Article abstract of DOI:10.1016/S0957-4166(02)00312-9

The mechanism for the transformation of β-amino alcohol methanesulfonate hydrochlorides into sodium β-amino alkanesulfonates using sodium sulfite was investigated. The results show that sodium sulfite initially neutralizes the β-amino alcohol methanesulfonate hydrochloride to give a free β-amino alcohol methanesulfonate, which then cyclizes to a 2-alkylaziridine. Attack by the previously formed sodium bisulfite at the less hindered carbon atom of the aziridine ring then yields a β-amino alkanesulfate sodium salt. Based on this mechanistic proposal, a new and rapid asymmetric synthesis of (R)- and (S)-2-aminoalkanesulfonic acids from chiral amino alcohols was developed. Chiral amino alcohols were converted to chiral aziridines through the Wenker method or Mitsunobu reaction and the resulting aziridines were reacted with sodium bisulfite to produce chiral β-amino alkanesulfonic acids.