Novel methods for the synthesis of small ring systems

Chapter 1 briefly reviews telescoped reactions, in particular tandem oxidation
processes, detailing the background to the development of the methodology
presented here, and sets out the aims for the Thesis.
Chapter 2 reviews cyclopropanation methods and examines the preparation and use
of triisopropylsulfoxonium tetrafluoroborate II for the preparation of gemdimethylcyclopropanes
for a range of α,β-unsaturated compounds including ketones,
esters, amides, nitriles and nitro-compounds (Scheme I). Chapter 2 also examines
potential applications for the methodology, outlining a route towards the synthesis of
chrysanthemic acid as well as attempts towards rearrangement methodology.

Chapter 3 demonstrates the preparation of 3-substituted oxindoles from substituted
anilides in a copper-mediated cyclisation-decarboxylation sequence (Scheme II).

This sequence is demonstrated for a range of alkyl, aryl and heteroaryl substituents in
the 3-position, with methyl, benzyl and PMB protection on the nitrogen atom.
Further development of the copper-cyclisation methodology leading to a catalytic
system is presented, along with initial work towards a decarboxylative allylation of
oxindoles.