Facile Synthesis of the Tricyclic Core of Daphniphyllum Alkaloid Daphnilongeranin B via Oxidative Nazarov Reaction
Year: 2025
Type: article
Abstract: ABSTRACT Daphniphyllum alkaloid daphnilongeranin B presents synthetic challenges due to its congested hexacyclic skeleton, seven stereogenic centers, and two vicinal quaternary centers. Recently, we discovered a series of TEMPO + BF 4 − ‐promoted Nazarov reactions and demonstrated their value in the synthesis of five‐membered ring‐containing small molecules and structurally complex natural products. Herein, we report a concise synthesis of its [7‐5‐5] tricyclic core via a 7‐step approach, using commercially available, inexpensive cycloheptenone as the starting material. Key transformations include a Babler‐Dauben rearrangement, an intramolecular aldol condensation, and a pivotal TEMPO⁺BF4 − ‐mediated oxidative Nazarov reaction via an easily synthesized, unfunctionalized tertiary divinyl carbinol (TDC). These results showcase the utility of our mild Nazarov methodology and lay the foundation for the total synthesis of daphnilongeranin B.
Source: Chemistry - A European Journal
Authors: Ying Hou, Yan Zhang, Yuye Chen, Jing Xu
Institution: Southern University of Science and Technology
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
Funders: National Natural Science Foundation of China, Natural Science Foundation of Guangdong Province, Science, Technology and Innovation Commission of Shenzhen Municipality, Southern University of Science and Technology, Guangdong Provincial Key Laboratory Of Catalysis, Guangdong Province Introduction of Innovative R&D Team
OpenAlex ID: W4416407925