Abstract
An efficient regioselective endocyclic oxidation of enantiopure 3‐alkylpiperidines 1(a–c) with bromine in acetic acid to generate the corresponding 5‐alkylpiperidin‐2‐ones 3(a–c) as main product is described. In addition, starting from 3a or 3b, the synthesis of (3S,5S)‐(‐)‐3‐ethyl‐5‐methylpiperidine 6 · HCl was achieved. Finally, the X‐ray single‐crystal analysis of compound 4 is reported.
Acknowledgments
We are grateful to CONACyT for financial support (Project J35088‐E) and BUAP (Project VIEP II‐110G02). A.C.C. thanks to CONACyT for the doctoral scholarship (166996).