A simple stereoselective route to α-trifluoromethyl analogues of piperidine alkaloids
The highly diastereoselective synthesis of five trifluoro-substituted analogues of mono-, di-, and trisubstituted piperidine alkaloids was accomplished in two to four steps from 2-trifluoromethyl keto-protected 4-piperidones, prepared by an intramolecular