A rapid entry to C-prenylcarbazoles: total synthesis of clausamine C-D, clausevatine D and clausine F

摘要

The key prenylcarbazole precursor 33 was readily assembled from diester 30 by an ester-driven para-Claisen rearrangement followed by selective removal of the ester function. Unusual oxidative cyclization of 33 by m-CPBA resulted in the total synthesis of tetracyclic carbazole natural products 3 and 11.rnThe carbazole alkaloids are a well-known class of secondary metabolites of plant origin. They display a wide variety of biological activities, namely antitumor, antibacterial, anti-inflammatory and antifungal activities. Moreover, carbazole nuclei are prevalent in various functional organic materials and potential medicinal agents.