Studies on new approaches for the radiolabelling of (+)-catechin

Forrest, Neil David (2004) Studies on new approaches for the radiolabelling of (+)-catechin. PhD thesis, University of Glasgow.

Abstract

Flavonols are polyphenolic plant secondary metabolites found in high concentrations in fruits, vegetables and beverages such as tea and red wine. Many possess antioxidant and free radical scavenging activity and epidemiological studies indicate that consumption of flavonols is associated with a reduced risk of coronary heart disease. (+)-Catechin is one such compound found in red wine and green tea. The absorption and metabolism of (+)-catechin is poorly understood and radiolabelled material is required to determine its bioavailability and role as an in vivo antioxidant. We envisaged two main approaches in our retrosynthesis of labelled (+)-catechin from aryllithium and radiolabelled carbon dioxide. The first involved flavene as a key intermediate whilst the second relied on the preparation of 1,3-diarylpropene. A number of routes to model flavenes v were attempted. A range of potential synthetic intermediates were prepared, but all failed to give the cyclised product. Various routes to synthetic intermediates corresponding to the 1,3-diarylpropene synthon were then investigated. The most successful approach proved to be crossmetathesis. Thus, phloroglucinol was protected as its tris-THP ether, lithiated and allylated to give a mixture of diastereomeric compounds. Cross-metathesis then gave 1,3-diarylpropene and dihydroxylation provided the racemic syn diol. Other potential substrates for alkenation reactions were prepared including phosphonium salt and sulfone and a range of novel benzothiazole chemistry is discussed.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: Richard Hartley
• Keywords: Organic chemistry
• Date of Award: 2004
• Depositing User: Enlighten Team
• Unique ID: glathesis:2004-74051
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 23 Sep 2019 15:33
• Last Modified: 23 Sep 2019 15:33
• URI: https://theses.gla.ac.uk/id/eprint/74051