Org Lett 2015 Sep 28;17(18):4428-31. Epub 2015 Aug 28.
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Science, Northwest A&F University , 22 Xinong Road, Yangling 712100, Shaanxi, China.
The first enantioselective synthesis of (-)-conolutinine was achieved in 10 steps. The synthesis featured a catalytic asymmetric bromocyclization of tryptamine to forge the tricycle intermediate. Hydration of an alkene catalyzed by Co(acac)2 was also employed as a key step to diastereoselectively introduce the tertiary alcohol moiety. The absolute configuration of (-)-conolutinine was established to be (2S,5aS,8aS,13aR) based on this asymmetric total synthesis.