Novel synthesis of highly functionalised furans and investigation into a cope rearrangement of furylvinylcyclopropanes

Klaus, Verena (2016) Novel synthesis of highly functionalised furans and investigation into a cope rearrangement of furylvinylcyclopropanes. PhD thesis, University of Glasgow.

Abstract

Furans are important heteroaromatic units that occur as subunits in various complex natural products, biologically active compounds and pharmaceuticals. Due to their pharmacophoric properties they find widespread application e.g. in the drug discovery process. In contrast to the classical condensation based-methods and metal-mediated approaches, organocatalytic methods for construction of furan have been relatively unexplored.
The opening chapter details investigation undertaken into furan formation methodology developed within the Clark group. It was determined that the choice of the acid species was vital for proton transfer to ensure clean and effective conversion of the substrates into the desired furans. Studies were carried out using a chiral acid in an attempt to deliver the furan product in an enantioselective manner. Since the formation of a new stereocentre is achieved in this process, we investigated the potential development of a diastereoselective reaction using substrates bearing an existing stereocentre. The original organocatalytic furan synthesis using THT and ynenedione with nucleophiles was successfully expanded by designing a substrate with a tethered nucleophile that initiates a second cyclization to form polycyclic systems.

Cyclohepta[b]furans are an important class of organic compounds found in many natural products, pharmaceuticals, bioactive compounds and functional materials. The development of efficient routes for their formation is therefore of great interest to the synthetic chemist.
The second chapter details research undertaken towards a new methodology for the construction of cyclohepta[b]furans. Starting from a simple linear ynenedione the cascade reaction affords furans containing a fused bicyclic system which rearrange to cycloheptadienes. Since it has been observed that the cyclisation and rearrangement occurred successfully it was hypothesised that it may be possible to carry out furan formation followed by Cope rearrangement in a one-pot fashion without isolation of the furan intermediate.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: methodology, furans.
• Subjects: Q Science > QD Chemistry
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Clark, Professor J. Stephen
• Date of Award: 2016
• Depositing User: Ms Verena Klaus
• Unique ID: glathesis:2016-7905
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 01 Feb 2017 11:45
• Last Modified: 27 Feb 2017 08:47
• URI: https://theses.gla.ac.uk/id/eprint/7905