A New Synthesis of Aziridines from β-Amino Alcohols with Triphenylphosphine Dibromide

The reaction of β-amino alcohols with triphenylphosphine dibromide was found to give the corresponding aziridines in good yields. The reaction opened a new route to the synthesis of aziridine compounds which seems to be more convenient than the Gabriel and Wenker methods. In the ring closure of ephedrine, a Walden inversion was observed. A possible mechanism is suggested.