Divergent Total Syntheses of (−)‐Daphnilongeranin B and (−)‐Daphenylline. (5th December 2017)

• Record Type: Journal Article
• Authors: Chen, Xiaoming; Zhang, Hai‐Jun; Yang, Xinkan; Lv, Houqiang; Shao, Xiaoru; Tao, Cheng; Wang, Huifei; Cheng, Bin; Li, Yun; Guo, Jingjing; Zhang, Jing; Zhai, Hongbin
• Is Part Of: Angewandte Chemie. Volume 130:Number 4(2018)
• Page Start: 959
• Page End: 963
• Publication Date: 2017-12-05
• Subjects: [3+2]-Cycloadditionen -- Alkaloide -- Asymmetrische Totalsynthesen -- Naturstoffe -- Umlagerungen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201709762
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: (−)‐Daphnilongeranin B and (−)‐daphenylline are two hexacyclic Daphniphyllum alkaloids, each containing a complex cagelike backbone. Described herein are the first asymmetric total synthesis of (−)‐daphnilongeranin B and a bioinspired synthesis of (−)‐daphenylline with an unusual E ring embedded in a cagelike framework. The key features include an intermolecular [3+2] cycloaddition, a late‐stage aldol cyclization to install the F ring of daphnilongeranin B, and a bioinspired cationic rearrangement leading to the tetrasubstituted benzene ring of daphenylline.