1360874-07-2Relevant academic research and scientific papers
Collective synthesis of lycopodium alkaloids and tautomer locking strategy for the total synthesis of (-)-lycojapodine A
Li, Houhua,Wang, Xiaoming,Hong, Benke,Lei, Xiaoguang
, p. 800 - 821 (2013/04/23)
The collective total synthesis of Lycopodium alkaloids (+)-fawcettimine (1), (+)-fawcettidine (2), (+)-alopecuridine (4), (-)-lycojapodine A (6), and (-)-8-deoxyserratinine (7) has been accomplished from a common precursor (15) based on a highly concise route inspired by the proposed biosynthesis of the fawcettimine- and serratinine-type alkaloids. An intramolecular C-alkylation enabled efficient installation of the challenging spiro quaternary carbon center and the aza-cyclononane ring. The preparation of the tricyclic skeleton as well as the establishment of the correct relative stereochemistry of the oxa-quaternary center were achieved by hydroxyl-directed SmI2- mediated pinacol couplings. An unprecedented tandem transannular N-alkylation and removal of a Boc group was discovered to realize a biosynthesis-inspired process to furnish the desired tetracyclic skeleton. Of particular note is the unique and crucial tautomer locking strategy employed to complete the enantioselective total synthesis of (-)-lycojapodine A (6). The central step in this synthesis is the late-stage hypervalent iodine oxidant (IBX or Dess-Martin periodinane)/TFA-mediated tandem process, which constructed the previously unknown carbinolamine lactone motif and enabled a biomimetic transformation to generate (-)-lycojapodine A (6) in a single operation.
Total syntheses of lycopodium alkaloids (+)-fawcettimine, (+)-fawcettidine, and (-)-8-deoxyserratinine
Li, Houhua,Wang, Xiaoming,Lei, Xiaoguang
, p. 491 - 495 (2012/02/16)
A shared story: Three fawcettimine- and serratinine-type Lycopodium alkaloids are prepared from a common tetracyclic spirodiketone intermediate in concise total syntheses (see scheme). The intermediate was constructed by a remarkable biosynthesis-inspired
