SummaryBestmann ylide [(triphenylphosphoranylidene)ketene] acts as a chemical linchpin that links nucleophilic entities, such as alcohols or amines, with carbonyl moieties to produce unsaturated esters and amides, respectively. In this work, the formation of α,β,γ,δ-unsaturated esters (dienoates) is achieved through the coupling of Bestmann ylide, an alcohol and an α,β-unsaturated aldehyde. Primary and secondary alcohols, including allylic alcohols, are suitable substrates; the newly formed alkene has an E-geometry. Strategically, this represents a highly efficient route to unsaturated polyketide derivatives. A linchpin approach to the synthesis of a major fragment of the natural products zampanolide and dactylolide is investigated using Bestmann ylide to link the C16–C20 alcohol with the C3–C8 aldehyde fragment.

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Approach. -The Bestmann ylide (III) is used as a linking entity between C3-C8 aldehyde and C16-C20 alcohol fragments to synthesize unsaturated esters. This highly efficient single-step protocol contrasts with other routes that require multi-step sequences. -(WANG, J.; TING, S. Z. Y.; HARVEY*, J. E.; Beilstein J. Org. Chem. 11 (2015Chem. 11 ( ) 1815Chem. 11 ( -1822 Sch. Chem. Phys. Sci., Victoria Univ.,

<p>Aigialomycin D is a fungal natural product possessing kinase inhibition properties. It is a member of a class of compounds known as the resorcylic acid lactones, a expansive group containing compounds exhibiting a vast array of biological activities. These include kinase and Hsp90 inhibition, highly desirable properties in the drug development field. This research project sought to capitalise on previous work involving the successful total synthesis of aigialomycin D. By developing the synthetic methodology, analogues of aigialomycin D could be prepared for biological testing to obtain valuable structure-activity relationship information. The focus of this thesis involves the successful synthesis of aigialomycin D diastereomer, 5',6'-epi,epi-aigialomycin D and the attempted synthesis of 100-epi-aigialomycin D, via the synthetic strategy developed previously in combination with enantiomeric starting material fragments ... The synthesis of functional group analogues, 6'-oxo-aigialomycin D, 7',8'-cyclopropyl aigialomycin D and 5-chloro-agialomycin D were also attempted via derivatisation of late-stage intermediates in the aigialomycin D synthesis. The thesis herein recounts the successes and failures in the synthesis of various aigialomycin D analogues ...</p>