Successive Ring Expansion (SuRE) in the synthesis of medium sized ring and macrocycle libraries

This thesis describes the development of new methodologies to synthesize different medium sized rings and macrocycles, either using Successive Ring Expansion (SuRE) reactions or SuRE-like reactions. In Chapter 2, new N-acylation conditions had been developed for lactams that cannot easily ring expand using previously reported Nacylation conditions. In Chapter 3, SuRE reactions were utilised to synthesize the 15-membered macrocyclic core of natural products Solomonamides and a series of analogues. Chapter 4 describes the development of a conjugate addition/ring expansion (CARE) cascade reaction, which allows the synthesis of diverse functionalized medium sized rings and macrocycles. In Chapter 5, two new ring expansion protocols (nitro reduction method and conjugate addition method) to access medium sized and macrocyclic sulfonamides are described. Chapter 6 describes the ring expansion study of P=O containing molecules, which showed quite different reactivity comparing to normal SuRE reaction. Chapter 7 describes a SuRE strategy to synthesize medium sized and macrocyclic aza sugars.