Thesis

New metal-mediated cyclisation methods and their strategic application in novel steroidal natural product synthesis

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2010
Thesis identifier
  • T12787
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • A programme of work towards the total synthesis of the natural product, agariblazeispirol C, has been performed, with significant advances towards the realisation of this overall goal having been achieved. Within the overall strategy for gaining access to the desired natural target, a number of individual preparative pathways have been taken. Optimisation studies on many of the individual reaction steps have been performed to enhance synthetic efficiencies within the formulated routes towards agariblazeispirol C. In particular, key metal-mediated cyclisation steps, an intramolecular Heck reaction and a selective cobalt-meditated Pauson-Khand annulation, are central to the established approach to the natural product system. With regards the Heck process, microwave technology has been utilised to enable the reaction time to be reduced from days to minutes and has also allowed a significant reduction in catalyst loading to be achieved. A more traditional approach towards the establishment of a successful intramolecular Pauson-Khand reaction has delivered some interesting results, as well as a cyclisation process which can be performed with good levels of efficiency. These synthetic advances have allowed the construction of the angularly-fused tetracyclic central core of the natural product system in an overall yield of 25% over 14 synthetic steps, when the most effective preparative pathway is considered. In addition to the many successes achieved during this body of work and despite advanced synthetic intermediates having been prepared, efforts towards the completion of the total synthesis of agariblazeispirol C and, more specifically, methods for the attachment of the oxygenated five carbon side-chain, have yet to be successful.
Resource Type
DOI
Date Created
  • 2010
Former identifier
  • 823909

Beziehungen

Objekte