title: Synthesis of the anti-HIV agent (-)-hyperolactone C by using oxonium ylide formation-rearrangement.
abstract: Starting from readily available (S)-styrene oxide an asymmetric synthesis is described of the naturally occurring anti-HIV spirolactone (-)-hyperolactone C, which possesses adjacent fully substituted stereocenters. The key step involves a stereocontrolled Rh(II) -catalysed oxonium ylide formation-[2,3] sigmatropic rearrangement of an α-diazo-β-ketoester bearing allylic ether functionality. From the resulting furanone, an acid-catalysed lactonisation and dehydrogenation gives the natural product.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, UK. david.hodgson@chem.ox.ac.uk
authors.forename: David M
authors.initials: DM
authors.lastname: Hodgson
authors.forename: Stanislav
authors.initials: S
authors.lastname: Man
mesh_terms: D019380:Anti-HIV Agents / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D004852:Epoxy Compounds / Q000737:chemistry*; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009861:Onium Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D019380:Anti-HIV Agents; D004852:Epoxy Compounds; D005663:Furans; D009861:Onium Compounds; C488315:hyperolactone C; C027727:hydronium ion; C013690:styrene oxide; D012238:Rhodium