Enantioselective Approach to Quinolizidines: Total Synthesis of Cermizine D and Formal Syntheses of Senepodine G and Cermizine C
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- 作者：Nagarathanam Veerasamy ; Erik C. Carlson ; Nathan D. Collett ; Mrinmoy Saha ; Rich G. Carter
- 刊名：The Journal of Organic Chemistry
- 出版年：2013
- 出版时间：May 17, 2013
- 年：2013
- 卷：78
- 期：10
- 页码：4779-4800
- 全文大小：1247K
- 年卷期：v.78,no.10(May 17, 2013)
- ISSN：1520-6904
文摘
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鈥揘 coupling has been explored on functionally dense coupling partners. Diastereoselective conjugate additions to 伪,尾-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.