Get access

Facile [7C+1C] Annulation as an Efficient Route to Tricyclic Indolizidine Alkaloids


  • Financial supports of this research provided by the NNSFC (21072027, 21172030, 21272034 and 21202015) and the Fundamental Research Funds for the Central Universities (11SSXT142) are greatly acknowledged.


original image

A handle on annulation: The two alkenoyl moieties of the cyclic dithiolane are parallel to each other and enables the [7C+1C] annulation with ethyl isocyanoacetate to occur. As a result, tricyclic indolizidine alkaloids are constructed by a two-step, base-catalyzed [7C+1C] annulation/intramolecular cyclization with subsequent reduction/cyclization.