Restriction lift date: 2033-12-31
Synthesis of novel cycloperoxides
Hennessy, Mary C.
University College Cork
Cycloperoxides represent an important class of compounds for synthetic chemists. Their asymmetric synthesis will be the focus of this thesis, specifically using organocatalysis. Chapter 1 contains a review of organocatalysed peroxidations from the literature and within the research group to date. The key aims and objectives of this project are also outlined. Chapter 2 describes the generation of a diverse library of trans-γ,δ-unsaturated β-keto esters. The preparation of these compounds involves both Wittig chemistry and Lewis acid-catalysed C-H insertion strategies. The synthesis of a cis-γ,δ-unsaturated β-keto ester and a non-enolisable α,α-disubstituted β-keto ester are also outlined. The optimisation of the organocatalysed peroxidation of γ,δ-unsaturated β-keto esters in terms of enantioselectivity and yields is described in Chapter 3. To determine the enantioselectivity of the peroxidation reaction, a robust chiral HPLC methodology is required. The development of a suitable separation methodology is outlined in this chapter. Chapter 4 describes a novel synthetic route to 3,5-substituted 1,2-dioxolane ethyl esters through the chemoselective reduction of a δ-peroxy-β-keto ester to the corresponding δ-peroxy-β-hydroxy ester, and subsequent phosphorus pentoxide-mediated cyclisation. Chapter 5 outlines our preparation of several novel 1,2-dioxolane carboxylic acids and various attempts at subsequently introducing an N-acyl sulfonamide to the 1,2-dioxolane core. Chapter 6 details the main conclusions of this work and proposes several avenues of research to investigate in future. Chapter 7 contains all relevant experimental procedures, including spectroscopic and analytical data.
Cycloperoxides , Peroxidation , 1,2-Dioxolane , Cyclisation , γ,δ-unsaturated β-keto esters , Asymmetric synthesis , Organocatalysis
Hennessy, M. C. 2023. Synthesis of novel cycloperoxides. PhD Thesis, University College Cork.