Synthetic studies towards methylene cyclic sulfamidites and sulfamidates
thesisposted on 27.02.2018, 15:10 by Frances M. Normansell
Chapter one provides a general introduction, which reviews relevant literature concerning the preparation and chemistry of cyclic sulfamidites and sulfamidates. A comparison is drawn between these compounds and the analogous cyclic sulfites, cyclic sulfates, epoxides and aziridines, in terms of their chemistry. Work undertaken by other members of the research group in this area is discussed and a review of the preparation of allene oxides and methyleneaziridines is given. Project aims, in terms of the preparation of a methylene cyclic sulfamidate are discussed in relation to the successful preparation of a methylene cyclic sulfite within our group. Chapter two describes the preparation of a simple cyclic sulfamidate and goes on to detail three routes undertaken towards the synthesis of novel 4-methylene cyclic sulfamidates. The first approach involved subjecting a β-hydroxy-imine to the conditions used to convert an amino alcohol to a cyclic sulfite, which unexpectedly did not result in formation of the desired 4-methylene cyclic sulfamidite. An alternative route for the preparation of 4-methylene cyclic sulfamidites was explored using an elimination reaction employing selenoxides to introduce the double bond as the final synthetic step. We successfully completed the synthesis of two precursors possessing different substituents attached to the selenium atom, although neither could be successfully eliminated to the desired methylene cyclic sulfamidite. Chapter three describes the detailed experimental work undertaken in this thesis.