First Stereoselective Synthesis of (1R,2R,4R)‐ and (1S,2R,4S)‐2‐Substituted‐1‐azabicyclo[2.2.1]heptanes

The first stereoselective synthesis of two diastereomeric 1-azabicyclo[2.2.1]heptanes substituted at the 2-position from an easily accessible (R)-2-substituted-4-piperidone is reported. The synthetic route involves the asymmetric one-carbon homologation of a chiral ketone followed by an intramolecular SN2-type cyclisation and led to target compounds in high overall yield by using a simple procedure in which purification of the intermediate compounds is not required. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)