The research presented here regards the biosynthetic origins of several secondary
metabolites isolated from red algae of the genus Laurencia. This thesis has been separated
into two major parts, and includes an appendix cataloguing the experimental procedures
and spectroscopic data.
Part I covers the epoxidation of bromoallenes, as inspired by the previously
unknown biosynthetic link between two natural products isolated from Laurencia obtusa, one
bearing a bromoallene and the other an α,β-unsaturated ester. Employing model
bromoallene 1 and a range of epoxidation methods, a procedure was developed that would
generate α,β-unsaturated acids 2 in low, but reproducible yields. Isotopic labelling of the
substrate with deuterium and carbon-13 allowed elucidation of the mechanism, by
observation of the migration of these atoms.Part II of this thesis reports the completion of the total synthesis of a range of
Laurencia secondary metabolites. The initial targets of this project proved to be unobtainable,
most likely due to the sensitivity of the allyl ether group under reductive conditions. An
alternative route was successfully applied to bypass this problematic step, allow the
synthesis of a range of Laurencia natural products and provide insights into their
biosynthesis. Positive identification of these compounds was achieved by a Δδ analysis of
the collected 1H & 13C NMR spectra, with that reported in literature.