Novel stereoselective synthesis of 1,2,3-trisubstituted azetidines

A novel, superbase induced diastereoselective transformation of benzylamino groups containing oxiranes has provided a series of trans-1,2,3-trisubstituted azetidines in good yields. The reaction of the corresponding optically active cis-2,3-disubstituted oxirane yielded the azetidine derivative as a single enantiomer. The structures of the new azetidines were confirmed by NMR spectroscopic methods and, in one case, by single crystal diffraction measurements.