Abstract A set of azetidinium ions substituted at the nitrogen atom either by a benzyl group or a benzhydryl group were synthesized to delineate the scope of their ring expansion into 2- phenyl-or 2, 2-diaryl-pyrrolidines through a Stevens rearrangement. Whereas the regioselectivity of the rearrangement is very high, the diastereoselectivity is low when 2, 3- disubstituted pyrrolidines are produced, except in one case. The major undesirable side- ...