P. Lienard et al., PREPARATION OF OPTICALLY-ACTIVE 6-SUBSTITUTED 2-PIPERIDONES BY OXIDATION OF THE CORRESPONDING OXAZOLOPIPERIDINES, Synlett, (2), 1994, pp. 143-144
Optically active 6-substituted 2-piperidones 4 and 5 were prepared in
good yields (52%-80%) by treatment of corresponding aminoethers 2 and
3 with bromine in CHCl3.