A Short Total Synthesis of (±)-Epimeloscine and (±)-Meloscine Enabled by a Cascade Radical Annulation of a Divinylcyclopropane

摘要

The first stereoselective synthesis of epime-loscine has been accomplished in 13 total steps with a longest linear sequence of 10 steps. The core of the synthesis takes only five steps, the key ones being acylation, stereoselective tandem radical cyclization of a divinylcyclopropane to make two rings, and group-selective ring-dosing metathesis of the resulting divinykydopentane to make the last ring.