An improved total synthesis of (+)-macroline and alstonerine as well as the formal total synthesis of (-)-talcarpine and (-)-anhydromacrosalhine-methine.
An intramolecular Pd-catalyzed alpha-vinylation process is described. This cyclization has been employed for the enantiospecific total synthesis of gram quantities of both (+)-macroline 3 and the macroline equivalent 4. This sequence is compared to the enolate-driven cross-coupling process. The intermediate 4 was also converted into (-)-alstonerine 1 via modification of an intramolecular Tsuji-Wacker oxidation. This sequence resulted in an improved total synthesis of (-)-talcarpine 5 and (-)-anhydromacrosalhine-methine 6 as well.
Liao
Xuebin
X
Department of Chemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA.
Zhou
Hao
H
Yu
Jianming
J
Cook
James M
JM
D026121:Indole Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D013237:Stereoisomerism
D026121:Indole Alkaloids; C510442:alstonerine; C522023:anhydromacrosalhine-methine; C522024:talcarpine