Asymmetric Total Synthesis of Hispidanin A. Issue 21 (20th April 2017)

• Record Type: Journal Article
• Authors: Deng, Heping; Cao, Wei; Liu, Rong; Zhang, Yanhui; Liu, Bo
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 21(2017)
• Page Start: 5849
• Page End: 5852
• Publication Date: 2017-04-20
• Subjects: diterpenoids -- labdane -- radical cascade -- total synthesis -- totarane; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201700958
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Asymmetric total synthesis of the dimeric diterpenoid hispidanin A was accomplished by non‐catalytic Diels–Alder cycloaddition at room temperature. The synthesis relies on iron‐catalyzed coupling to construct a Z ‐configured trisubstituted alkene, an iron‐catalyzed radical cascade to generate a labdane‐type diene, and both Yamamoto cationic polyene cyclization and palladium‐catalyzed Stille coupling to generate a totarane‐type dienophile. Abstract : Radical is radical : Asymmetric total synthesis of a dimeric diterpenoid, hispidanin A, has been accomplished through spontaneous [4+2] cycloaddition without catalysis at room temperature. Construction of the diene fragment features a designed radical polyene cyclization triggered by metal‐catalyzed hydrogen atom transfer, while subsequent asymmetric cationic polyene cyclization generates the dienophile fragment.