Mrinmoy Saha - Enantioselective Approach to Quinolizidines: Total Synthesis of Cermizine D and Formal Syntheses of Senepodine G and Cermizine C

Version 1

      Publication Details (including relevant citation   information):

        J. Org. Chem.,    2013,    78   (10), pp 4779–4800

      Abstract:

      The formal syntheses of C5-epi-senepodine G and C5-epi-cermizine   C have been accomplished through a novel diastereoselective,   intramolecular amide Michael addition process. The total   synthesis of cermizine D has been achieved through use of an   organocatalyzed, heteroatom Michael addition to access a common   intermediate. Additional key steps of this sequence include a   matched, diastereoselective alkylation with an iodomethylphenyl   sulfide and sulfone-aldehyde coupling/reductive desulfurization   sequence to combine the major subunits. The utility of a   Hartwig-style C–N coupling has been explored on functionally   dense coupling partners. Diastereoselective conjugate additions   to α,β-unsaturated sulfones have been investigated, which   provided the key sulfone intermediate in just six steps from   commercially available starting materials. The formal syntheses   of senepodine G and cermizine C have been accomplished through an   intramolecular cyclization process of a N-Boc-protected   piperidine sulfone.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/jo400324t