Synthesis of Tetracyclic Core Structure of Daphnezomines A and B

Among the tiniest Daphniphyllum alkaloid subfamilies, daphnezomine A-type alkaloids consist of only three known members, namely daphnezomine A (1), daphnezomine B (2) and dapholdhamine B. These alkaloids contain a unique aza-adamantane core along with nine contiguous stereogenic centers, thus presenting remarkable synthetic challenges. The synthesis of tetracyclic core structure of 1 and 2 was reported. The key steps in our approach include a Huang's amide-activa tion-annulation and a Hutchins-Kabalka reductive rearrangement.

Automated summary

Among the small subfamily of Daphniphyllum alkaloids, the daphnezomine A-type alkaloids have only three known members, namely daphnezomine A, daphnezomine B, and dapholdhamine B. These alkaloids possess a unique aza-adamantane core and nine contiguous stereogenic centers, which present significant synthetic challenges. The synthesis of the tetracyclic core structure of compounds 1 and 2 has been reported, with key steps including a Huang's amide-activation-annulation and a Hutchins-Kabalka reductive rearrangement.