Studies Towards Synthesis of Favipiravir & Humilisin E

Abstract

Synthetic organic chemistry has made human life easier by giving access to a variety of useful molecules. Be it academic research, industrial or medicinal applications, synthesis has paved way for accelerated growth in respective fields. The majority of drugs we use in our daily life are either natural products, analogues of natural products or mimic natural products in a certain way. Access to natural products from Nature can be laborious and inefficient, leading to a plethora of practical issues. Total synthesis bridges this gap by providing a way to access the required molecules from commercially available compounds. The first chapter discusses the synthetic routes towards favipiravir, an antiviral with a large global demand. Motivated by COVID-19 pandemic, we became interested in addressing the chemical synthesis of this molecule. The chapter outlines the previously reported synthetic routes and describes the rationale behind the design of a shorter route. The second chapter describes synthetic approaches towards the recently discovered tricyclic terpenoid humilisin E. Examples of natural products containing a bicyclo[3.2.0]heptane motif which constitutes the core of the humilisin E, and compiled examples from the literature for synthetic construction of this motif are reviewed. This discussion is followed by a detailed description of our own strategies to construct the bicyclo[3.2.0]heptane core of humilisin E, culminating in a successful stereocontrolled synthesis of the fully functionalized humilisin E core.

The entire thesis is summarized in chapter 3, and full experimental details are provided in chapter 4.

Keywords: total synthesis, natural products, terpenoids, pyrazines, cyclobutanes, cyclopentanes