Synthetic studies towards marine natural products

Electronic versions


  • Andrew John Thornhill


This thesis describes the work performed developing synthetic approaches to the guanidine containing marine natural products cylindrospermopsin and batzelladine F, and the bicyclic lactone containing compounds, the plakortones.
(i) A reductive guanidine addition-cyclisation reaction was employed to prepare the left hand portion of batzelladine F from a bis-a,j3-unsaturated ketone which was prepared from succinaldehyde using Wittig methodology.
(ii) Attempts were made to prepare a 6,6-bicyclic analogue of cylindrospermopsin in four steps from 5-hexen-1-ol utilising as the key step a tandem 1,4-addition/epoxide opening methodology. This was found to lead to a 7,6 product via a competitive process.
(iii) Intramolecular epoxide opening reactions involving guanidines were also studied providing access to several glycomimetic analogues. These included a simple five and seven membered ring system, together with a more complex substituted five and six membered ring system as well as a dimeric 7, 7 system.
(iv) A bicyclic 5,5-furanofuran was prepared via the reaction of n-butylmagnesium bromide with an a-hydroxy-y-ketocarboxylic acid which leads to the formation of a tetrasubstituted y-butyrolactone which in turn was converted to the required system, an analogue of the bicyclic lactones found in the marine natural products, the plakortones.


Original languageEnglish
Awarding Institution
  • Paddy Murphy (Supervisor)
Thesis sponsors
  • Engineering and Physical Sciences Research Council (EPSRC)
Award dateOct 2000