Samarium diiodide mediated radical cyclisations of a B-unsaturated carbonyl compounds

• Main Author: Powell, Jonathon Raymond
• Published: University of Southampton 2008
• Subjects: 547.6
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494762

This thesis is concerned with the synthesis, and samarium diiodide mediated radical cyclisations of α,β-unsaturated carbonyl compounds. Particular interest is directed at the development of a range of cyclic α,β-unsaturated carbonyl systems which have been designed as mechanistic probes to elucidate the nature of the key dimerisation step in the cascade sequence towards polycyclic products. Chapter 1 presents an overview of radical chemistry, including history and key principles. A discussion on samarium diiodide chemistry is also provided, which focuses on key mechanistic aspects and the reactivity of α,β-unsaturated carbonyl compounds with the reagent. A programme of work is also discussed. Chapter 2 describes the design and synthesis of a range of cyclic α,β-unsaturated carbonyl systems, and their uses as mechanistic probes for testing the intermediacy of radical species 253 and 254 and anionic species 255. Chapter 3 depicts the development of a variety of acyclic α,β-unsaturated carbonyl systems, and their reactivity upon exposure to samarium diiodide.