Novel synthetic routes to furan fatty acids and their analogues

Furan and its derivatives are commonly found in numerous compounds such as natural products, polymers and medicines. The furan ring system is not only the core component to many natural products, but also serves as a key synthetic intermediate to access other more complex molecules. Among furan derivatives, furan fatty acids (F-acids) are an important class of natural products which are widely distributed in nature, and occupy a unique place in the field of medicinal chemistry because of their potent biological and pharmacological activity. This thesis examines the development of novel approaches towards highly substituted furans, with the ultimate goal of applying novel and high efficiency methods to the synthesis of F-acids and their derivatives. The first total synthesis of a natural product, an F-acids metabolite originally isolated from shark (Lamna ditropis) bile, was accomplished by the utilisation of an iodocyclisation of the corresponding 3-alkyne-1,2-diol to construct the furan nucleus; the synthetic route will be discussed in this thesis. Through the study of palladium-catalysis of a formal cyclisation to construct the furan ring system, a general route to access different F-acids has been developed. Splitting the F-acids into relatively simple fragments allows for easy preparation and modification of two fragments to produce a range of F-acids. The synthetic route was then applied to the formal synthesis of a natural product, F-acid F6. After optimisation of the synthetic route, total synthesis of F-acids F4, F6 and their analogues was accomplished.