4-π-Photocyclisation of Troponoids – Scope and Applications

This thesis describes the synthesis of novel [3.2.0]bicycles via 4-π-photocyclisation of tropone and its 2-substituted derivatives. Chapter 1 provides a bibliographic overview of the literature pertaining to the synthesis of cyclobutenes, with a particular emphasis on the 4-π-photocyclisation of cyclic 1,3-butadienes. Chapter 2 investigates the optimisation and gram-scale synthesis of phototropone via 4-π-photocyclisation of tropone·BF3 in a batch photoreactor. The phototropone product obtained was subjected to a wide variety of reactions to yield novel small- molecule building blocks. Chapter 3 describes the synthesis of 2-substituted tropones by known litera- ture procedures as well as custom syntheses. The 2-substituted tropones obtained were irradiated both in the presence and absence of BF3·OEt2 to obtain a series of novel [3.2.0]bicycles, and valuable insights into the substituent effects on this reaction were gleaned. Chapter 4 provides overall conclusions from Chapters 2 and 3, as well as ideas for potential future work. Chapter 5 describes the experimental details and characterisation of novel com- pounds described in this thesis