This thesis describes stereoselective synthetic approaches to the bicyclic and tricyclic guanidine cores of batzelladines A and C. Chapter 1 introduces the batzelladine alkaloids, discussing important biological properties, literature syntheses and previous synthetic studies within the Elliott group. Chapter 2 describes our key synthetic step, a modified version of the Kishi three-component coupling in detail. In addition to studies to determine the stereochemistry of this reaction, experimental evidence has been gathered to ascertain the reaction mechanism. Chapter 3 discusses a diastereoselective synthetic route to the western half of batzelladine A. The three-component coupling proceeds with total diastereocontrol, enabling the bicyclic pyrrolo 1,2-c pyrimidine core of the left-hand side of the natural product to be constructed in an efficient manner. The stereoselectivity of this central synthetic step also offers further evidence towards the proposed reaction mechanism. Chapter 4 describes a first-generation synthetic approach towards batzelladine C, utilising a novel stereoselective reaction of a chiral A-acyliminium ion and allenylsilane as a key step. In Chapter 5, the second-generation synthetic route to Batzelladine C is discussed. With no requirement for protecting groups, a tricyclic guanidine core corresponding to batzelladine C is synthesised diastereoselectively. It is anticipated that only a few more steps will be required to achieve the total synthesis of the natural product.