Medium-ring lactones have become important targets for synthesis as they have been
isolated in an increasing number of biologically active natural products. The studies
towards two 8-membered ring lactone natural products, octalactins A 1 and B 2, will
be described.The first section of this thesis examines the application of key methodology (anti
aldol reaction, Homer Wadsworth Emmons olefination, intermolecular Evans-
Tishchenko coupling and Ring Closing Metathesis) towards the octalactins via the
synthesis of a model lactone 3 (Chapter 2). The second section (Chapter 3) discusses the extension of the aldol methodology
from Chapter 2 towards the development of a novel chiral auxiliary 4 to mediate the
anti aldol reaction. The generality of this new auxiliary in anti aldol reactions will
also be discussed.
The final part of this thesis describes the synthesis of the octalactins based on the
application of the methodology developed from the model studies using the key
functionalised fragments: aldehyde 5, 3-ketophosphonate ester 6 and aldehyde 7
