Asymmetric total syntheses of five pyrrole-type Stemona alkaloids†
Xiaodong Wang,Tao Shi,Gaofeng Yin,Yuqing Wang,Zhao Li
Organic Chemistry Frontiers Pub Date : 05/23/2022 00:00:00 , DOI:10.1039/D2QO00456A
Abstract

The asymmetric total syntheses of five pyrrole-type Stemona alkaloids and two stereoisomers were accomplished, among which 3-n-butylneostemonine and bisdehydroneostemonine were synthesized for the first time, and the NMR data of bisdehydroneostemonine were revised. Specifically, the 5/7 skeleton of stemoamide was established by employing Prins cyclization, and didehydrostemoamide was obtained from stemoamide using our method of Lawesson's reagent promoted pyrrole synthesis. Using didehydrostemoamide as the common intermediate, five pyrrole Stemona alkaloids were divergently synthesized. This research has enriched the transformation pattern of Stemona alkaloids.

Graphical abstract: Asymmetric total syntheses of five pyrrole-type Stemona alkaloids