Nature-Inspired Stereospecific Total Synthesis of P-(+)-Dispegatrine as well as the Total Synthesis of Four Other Monomeric Sarpagine Indole Alkaloids

摘要

>Non-phenolic oxidative coupling: The first total synthesis of the C-2 symmetric indole alkaloid P-(+)-dispegatrine (>1) is reported. A late-stage thallium(III)acetate mediated intermolecular oxidative coupling was employed to construct the C(9)-C(9′) bond with complete regio- and stereocontrol. The exclusive formation of a single atropodiastereomer >12 in this critical step arises due to internal asymmetric induction, as planned. In addition, the first total synthesis of four other monomeric sarpagine indole alkaloids is described.