UC Berkeley

Total synthesis is often pursued for one of two motivations: to showcase a strategy and/or methodology or to investigate the function of a natural product. The work described in this dissertation will span an array of natural products but focus on both of these motivations.Chapter 1 briefly discusses “chiral pool” syntheses to give context for some of the work outlined in Chapters 2, 3, and 4 of this dissertation. Chapter 2 discloses work toward rearranged ent-kaurene jungermatrobrunin A, utilizing a “chiral pool” starting material. We employed a “chiral pool” building block to synthesize a common decalin intermediate in enantioenriched fashion. Several potential routes to carry the decalin on to the jungermatrobrunin A framework are discussed. Additionally, the formal synthesis of two natural products, erigerol and forskolin, from the decalin intermediate are described. Chapters 3 and 4 outline the work completed toward the terpene xishacorene B. Chapter 3 focuses on the rearrangements of chrysanthenone derivatives that were discovered while attempting to forge the [3.3.1]bicyclic core of the natural product. These rearrangements were studied experimentally and computationally. The mechanism and underlying principles that were elucidated then aided in the synthesis of the [3.3.1]bicyclic core. Chapter 4 focuses on efforts to take the [3.3.1]bicyclic core to the natural product, highlighting key directed C–H functionalization efforts. Chapter 5 outlines efforts toward the alkaloid scholarinine A through a key oxidative coupling route. An efficient synthesis of scholarinine A would enable our collaborators, Corteva AgriSciences, to probe insecticidal activity of the natural product. Several attempted routes to the carbocyclic framework of scholarinine A are discussed in addition to a potential route to the alkaloid pleiocarpamine. Overall, this dissertation spans an array of targets, detailing work toward both terpene and alkaloid derived natural products.