Gram-Scale Total Synthesis of Sarpagine Alkaloids and Non-Natural Derivatives.

This work describes the total synthesis of three members of the sarpagine alkaloid family and ten non-natural congeners through an improved synthetic sequence, which was designed for gram-scale production of materials suited for structure-activity relationship (SAR) studies. Furthermore, the manuscript details how the synthetic route was used to access the biogenetically completely unrelated Stemona alkaloid parvineostemonine (34), providing a showcase for efficient synthetic design.