Toward a total synthesis of Englerin A

Abstract

Englerin A is a guiane sesquiterpenoid isolated from the spurred potato-bush Phyllanthus engleri that has shown potent and selective activity against renal cancer cell lines. Our approach to the synthesis of englerin A features a Diels-Alder reaction between an axially chiral allene and a 3-siloxyfuran. We have found the oxabicyclo[2.2.1]heptane framework to be a sterically formidable structure and have discovered a novel decomposition pathway of acetyl-oxabicyclo[2.2.1]heptanes to 3(2H)-furanones.