R                  CO2Et              C(OEt)=SO2CH3  

                 Yields*(%)   d.e.(%)   Yields*(%)   d.e.(%)
   
     H               62                    75
    CH3              33         16         54         20
  CH2OCH3            54          8         22          8
  (CH2)4             43         25
     Ph              13         51         10         26
*Inspection of 13C NMR spectra of crude reaction mixtures shows a complete conversion of acetals into aziridines. Almost all diastereomers can be easily separated by HPLC and it was possible to obtain single compounds with optical purity of nearly 100%.