title: The first synthetic studies on pestalotiopsin A. A stereocontrolled approach to the functionalised bicyclic core.
abstract: Pestalotiopsin A is a structurally unique, caryophyllene-type sesquiterpene which has shown immunosuppressive activity and cytotoxicity in preliminary assays. A stereocontrolled approach to the functionalised 2-oxabicyclo[3.2.0]-heptane core of pestalotiopsin A is described. This constitutes the first synthetic studies on pestalotiopsin A. Our approach includes a samarium(II)-mediated 4-exo-trig cyclisation and a trans-lactonisation process triggered by the addition of alkylytterbium reagents to a cyclobutanone intermediate. Further manipulation provides access to advanced intermediates which are excellent precursors for the future construction of the final ring of the target.
authors.affiliation: Department of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, UK G12 8QQ.
authors.forename: Derek
authors.initials: D
authors.lastname: Johnston
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Couché
authors.forename: David J
authors.initials: DJ
authors.lastname: Edmonds
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Muir
authors.forename: David J
authors.initials: DJ
authors.lastname: Procter
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D003503:Cyclobutanes / Q000737:chemistry; D006536:Heptanes / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry; D015394:Molecular Structure; D012493:Samarium / Q000737:chemistry; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001643:Bridged Bicyclo Compounds; D003503:Cyclobutanes; D006536:Heptanes; D007202:Indicators and Reagents; D012717:Sesquiterpenes; C430595:pestalotiopsin A; D012493:Samarium