Diastereoselective elaboration of 2,3,4-substituted piperidines using diene iron tricarbonyl complexes. Total synthesis of (+/-)-dienomycin C and (+/-)-4-epi-dienomycin C
The diastereoselective formation of 2,3,4-substituted piperidines is achieved by condensation of the iron dienal complex 2 and the primary amine 3 via an intramolecular Mannich-type cyclisation. This method is illustrated by the first total synthesis of (+/-)-dienomycin C 1 and its C-4 epimer 9. (C) 1996 Elsevier Science Ltd