The title compounds (19) were synthesized by rearrangement of the 1-ethoxycarbonyl-4-aryl-3, 4-epoxypiperidines (7) to give the 3-aryl-3-formylpyrrolidine derivatives (12) for pharmacological testing. Compound (19b) exhibited moderate central nervous system depressing activity. The mechanism of the rearrangement of 1-substituted 4-aryl-3, 4-epoxypiperidine with boron trifluoride etherate is discussed.
