Synthetic Study Aiming at the Tricyclic Core of 12- epi-JBIR-23/24

Org Lett. 2021 Apr 16;23(8):3151-3156. doi: 10.1021/acs.orglett.1c00853. Epub 2021 Apr 7.

Abstract

The synthetic study toward highly enantio- and diastereoselective synthesis of the tricyclic framework of 12-epi-JBIR-23/24, a natural product analogue showing inhibitory activity against four malignant pleural mesothelioma cell lines, is presented herein. In this synthesis, a rhodium-catalyzed asymmetric three-component Michael/aldol reaction introduces three consecutive tertiary carbon centers, while the unique epoxyquinol core motif is successfully forged via [3,3]-sigmatropic rearrangement of an allylic xanthate, vinylogous Pummerer rearrangement, and a selective mesylation/epoxidation cascade of a triol.