Biomimetic total synthesis of natural products

Abstract

This thesis describes several syntheses of natural products. The overall synthetic approach is to mimic how these secondary metabolites could be derived in Nature, where we aim to gain insights into the biosynthesis of these natural products from the syntheses. The first synthesis of hyperjapones A-I was achieved by an oxidative hetero-Diels-Alder reaction. The transformation of hyperjapone A to hyperajaponols A and C was achieved via an epoxidation and an acid-catalysed rearrangement cascade reaction, forming 4 stereocenters and 2 rings in 1 step. The first synthesis of verrubenzospirolactone was achieved from a Diels-Alder reaction of the polyene in water. Capillobenzopyranol, the proposed biosynthetic precursor of verrubenzospirolactone was also synthesized and converted into verrubenzospirolactone by mirroring our proposed biosynthetic pathway. The first synthesis of rhodonoids C and D, and murrayakonine D was achieved. The key biomimetic step was the acid catalysed rearrangement of an epoxide, forming 3 stereocenters and 2 rings in 1 step. The biomimetic total synthesis of yezo’otogirin C was achieved via an oxidative radical cyclization cascade reaction, forming 2 rings, 2 stereocenters, 1 C=C bond, 1 C-C bond and 1 C-O bond in 1 step.