Natural product syntheses
Saved in:
| Title: | Natural product syntheses |
|---|---|
| Authors: | Li, Ivan Chan Kwong |
| Summary: | This thesis is concerned with synthetic approaches towards the indole alkaloid koumine and the sesquiterpene quadrone. An intramolecular Diels-Alder reaction is the key step in our synthetic approaches to koumine. Chapter one describes some aspects of indole alkaloids including a general background, biosynthesis of strychnos alkaloids as well as the discovery of koumine and its pharmacological action. Chapter two deals with three potential routes to koumine and the important intermediate rel-(1R,6R,10S)-N-methyl-1-allyl-3-aza-2-oxobicyclo[4.4.0]dec-7-ene-10-y1-methanol has been prepared by way of a Diels-Alder reaction of maleic anhydride and (E)-3,5-hexadienylamine with further functionalisation. Quadrone, a sesquiterpene with a novel tetra cyclic system as well as antitumour activity, has become a popular synthetic target since its discovery and the main theme of our approach is a carbene cyclisation to form and basic skeleton. Chapter three describes the discovery of quadrone, its biogenetic origin and some previous sytheses. Chapter four explores 2 routes to the bicyclic intermediate 4-t-butyl-dimethyl-silyloxy-6,6-dimethyl-2-(2-oxo-2-propyl)bicyclo[3.2.1]octan-8-one which has been synthesised via a Michael addition of 4,4-dimethyl-2-(2-methyl-2-propyl) cyclopentanone with acrolein and subsequent intramolecular aldol condensation. Attempted preparation of the required carbene precursor (from this intermediate) using either a Horner-Wittig reagent or several halomethyltriphenylphosphonium halides proved unsuccessful. |
| URL: | https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375675 |
| Database: | OpenDissertations |
| FullText | Text: Availability: 0 |
|---|---|
| Header | DbId: ddu DbLabel: OpenDissertations An: ddu.oai.ethos.bl.uk.375675 AccessLevel: 6 PubType: Dissertation/ Thesis PubTypeId: dissertation PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Natural product syntheses – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Li%2C+Ivan+Chan+Kwong%22">Li, Ivan Chan Kwong</searchLink> – Name: Abstract Label: Summary Group: Ab Data: This thesis is concerned with synthetic approaches towards the indole alkaloid koumine and the sesquiterpene quadrone. An intramolecular Diels-Alder reaction is the key step in our synthetic approaches to koumine. Chapter one describes some aspects of indole alkaloids including a general background, biosynthesis of strychnos alkaloids as well as the discovery of koumine and its pharmacological action. Chapter two deals with three potential routes to koumine and the important intermediate rel-(1R,6R,10S)-N-methyl-1-allyl-3-aza-2-oxobicyclo[4.4.0]dec-7-ene-10-y1-methanol has been prepared by way of a Diels-Alder reaction of maleic anhydride and (E)-3,5-hexadienylamine with further functionalisation. Quadrone, a sesquiterpene with a novel tetra cyclic system as well as antitumour activity, has become a popular synthetic target since its discovery and the main theme of our approach is a carbene cyclisation to form and basic skeleton. Chapter three describes the discovery of quadrone, its biogenetic origin and some previous sytheses. Chapter four explores 2 routes to the bicyclic intermediate 4-t-butyl-dimethyl-silyloxy-6,6-dimethyl-2-(2-oxo-2-propyl)bicyclo[3.2.1]octan-8-one which has been synthesised via a Michael addition of 4,4-dimethyl-2-(2-methyl-2-propyl) cyclopentanone with acrolein and subsequent intramolecular aldol condensation. Attempted preparation of the required carbene precursor (from this intermediate) using either a Horner-Wittig reagent or several halomethyltriphenylphosphonium halides proved unsuccessful. – Name: URL Label: URL Group: URL Data: <link linkTarget="URL" linkTerm="https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375675" linkWindow="_blank">https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375675</link> |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=ddu&AN=ddu.oai.ethos.bl.uk.375675 |
| RecordInfo | BibRecord: BibEntity: Languages: – Code: eng Text: English Subjects: – SubjectFull: 547 Type: general – SubjectFull: Koumine and quadrone synthesis Type: general Titles: – TitleFull: Natural product syntheses Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Li, Ivan Chan Kwong IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 01 Type: published Y: 1986 |
| ResultId | 1 |
