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Updated: Aug 4, 2025

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Divergent Total Syntheses of (-)-Daphnezomines A and B and (+)-Dapholdhamine B
Shaobin Su1, Chengcheng Lin1, Hongbin Zhai1,2,3,4
1The State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, 518055, China.
Abstract:
The daphnezomine A-type subfamily of Daphniphyllum alkaloids structurally features a unique aza-adamantane core skeleton and anticipates efficient strategies for completing their syntheses to thoroughly investigate their biological activities. Herein, divergent total syntheses of (-)-daphnezomines A and B and (+)-dapholdhamine B have been accomplished in 16-20 steps from a known epoxide via rapid construction of a common core intermediate. The present work features a Ti-mediated radical cyclization to establish the azabicyclo[3.3.1]nonane ring system, an intramolecular Heck reaction to install the bridgehead all-carbon quaternary stereocenter, a tandem deprotection/reduction/keto amine-carbinolamine tautomerization to furnish the aza-adamantane backbone, and an NIS-promoted 6-endo-trig aminocyclization to assemble the (+)-dapholdhamine B backbone.
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