A Simple Stereoselective Route to α‐Trifluoromethyl Analogues of Piperidine Alkaloids

Abstract

Abstract 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 Mannich‐type reaction methodology. A simple stereoselective elaboration of new 2‐(trifluoromethyl)‐4‐piperidinols and 4‐amino‐2‐(trifluoromethyl)piperidines is also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)