Part I of this dissertation includes the chronological synthetic background of mandelalide A as well as the synthesis of the C1-C14 glycosylated southern subunit of mandelalide. A key aspect of the synthesis includes a novel silver-catalyzed cyclization (AgCC) of a propargylic benzoate to construct the substituted cis-pyran ring system present...
Sunscreen products are used worldwide to protect the skin from ultraviolet radiation. However, some of the ingredients used in sunscreen products are fatal to coral reefs especially in areas where tourism is a large part of the economy. In this study, we explored a synthetic route to produce 4-deoxygadusol, which...
The first part of this manuscript is about the total synthesis of the aspidosperma alkaloids leuconoxine, melodinine E and mersicarpine. Our synthetic strategy used a radical translocation-conjugate addition cascade to construct the core of the natural product. Specifically, a vinyl radical was generated from the homolysis of the C–I bond...
Substituted phenols are important substructures for pharmaceuticals, agrochemicals, natural products and biological probe molecules. The properties of phenolic molecules are substantially influenced by the substitution patterns of the phenolic ring. The chemical synthesis of phenols with various substitution patterns is an enduring challenge and multiple strategies have emerged. However, some...
In the past decades, femtosecond stimulated Raman spectroscopy (FSRS) has been gaining tremendous popularity in fundamental sciences stemming from chemistry to biology. It is capable of capturing both equilibrium and non-equilibrium structural information across a broad range of timescales with simultaneously high temporal and spectral resolutions. Femtosecond transient absorption spectroscopy...
Exploring bioactive natural products has contributed largely to clinically approved drugs we have been using over the last 100 years. Especially among the anti-infective drugs, around 70% of currently used antibiotics were discovered or derived from microbial secondary metabolites, among them compounds like vancomycin, chloramphenicol, and erythromycin. Facing the unavoidable...
Fungi have long been used for discovery of new chemical scaffolds. In the clinical setting, the fungal natural products penicillin, statins, and cyclosporine have revolutionized medicine to treat diseases and infections. In the environment, fungal natural products have been used as herbicides, fungicides, and insecticides to protect crops, livestock, and...
Dearomatization reactions exist broadly in biosynthesis and chemical synthesis. The highly functionalized atoms of arenes can be masked by it aromaticity, and upon dearomatization, those reactive atoms can be readily applied to bond formation and further manipulation. The total synthesis of (–)-cephalotaxine and (–)- homoharringtonine is described via an oxidative...
Mandelalide A has attracted considerable interest from the synthetic community due to its intriguing structure and important cytotoxic activity. Madeirolide A, a structurally related macrolide, shows promising antifungal activity but no appreciable anticancer activity. This dissertation describes synthetic studies toward mandelalide A, madeirolide A and their hybrid structures.
Part I...
The furanyl diterpenoid family of natural products has drawn the attention of both synthetic organic chemists and pharmacologists due to their complex structural architectures and diverse biological activity. Among them, wortmannin has been most extensively studied for biological activities. All these furanyl diterpenoids consist of a highly strained naptha[1,8-bc]furan core,...