Total synthesis of the cytotoxic alkaloid Calyciphylline B
Final Report Abstract
The primary target of this project, the total synthesis of Calyciphylline B, was not achieved during the course of this study. Nevertheless, significant progress was made: The synthesis of compound 35 gave a key fragment of the initially developed convergent route. Here, four out of Calyciphylline’s eight stereogenic centers were installed including the challenging quaternary center. Additionally, a novel synthetic access towards 2,3,4-tri-substituted pyrrolidines with an all-syn substitution pattern was discovered. A further and more detailed investigation of this finding is currently ongoing in the Hanessian group. Nevertheless, it was shown that such all-syn-substituted pyrrolidines are well-suited starting materials for the synthesis of 5,5- and 5,6-cis-fused bicycles through classical Dieckmann condensations. In the latter case, the 5,6-ring system of compound 38 (and/or 41) might be a powerful precursor for an intriguing total synthesis of Daphniglaucin C.
