1: tert-butyl 3-hydroxy-1-piperidinecarboxylate With 2,2,6,6-tetramethyl-piperidine-N-oxyl; [bis(acetoxy)iodo]benzene in dichloromethane 16 h; 2: benzylamine With sodium tris(acetoxy)borohydride in dichloromethane chemoselective reaction;