A Simple Stereoselective Access to (alpha)-Trifluoromethylated Piperidines

An intramolecular Mannich-type reaction, involving either an (alpha)-trifluoromethyl-1,3-aminoketal or a fluoral synthetic equivalent, was employed to prepare diastereoselectively (alpha)-trifluoromethylpiperidines. This simple strategy allows a facile access to a wide range of new (alpha)-trifluoromethyl saturated N-heterocyclic compounds.