American Chemical Society
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Enantioselective Total Synthesis of (−)-Arcutinine

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posted on 2019-05-28, 00:00 authored by Wei Nie, Jing Gong, Zhihao Chen, Jiazhen Liu, Di Tian, Hao Song, Xiao-Yu Liu, Yong Qin
The first total synthesis of an arcutine-type C20-diterpenoid alkaloid arcutinine has been achieved in both racemic and asymmetric forms. Construction of the C4 quaternary center and the pyrrolidine E ring in an early stage proved to be important for achieving the successful synthesis of the target alkaloid. Strategically, an asymmetric conjugate addition/aldol cascade and a decarboxylative allylation reaction allowed the establishment of the vicinal all-carbon quaternary stereocenters at C4 and C5. Furthermore, a sequence consisting of an intramolecular aza-Wacker cyclization, an oxidative dearomatization/intramolecular Diels–Alder cycloaddition cascade, and a ketyl-olefin cyclization enabled the assembly of the core structure and led to the total synthesis of arcutinine.