title: Synthesis of (+)-obtusenyne.
abstract: An enantioselective synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported which uses the ring expansion of a seven-membered ketene acetal by means of a Claisen rearrangement to construct the core nine-membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition-metal-catalyzed intramolecular hydrosilation reaction of an exo-cyclic enol ether. In addition, a formal synthesis of ent-obtusenyne from 2-deoxy-D-ribose is reported. A number of interesting points regarding the chemistry of medium-ring oxygen heterocycles are highlighted.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
authors.forename: S Y Frankie
authors.initials: SY
authors.lastname: Mak
authors.forename: Neil R
authors.initials: NR
authors.lastname: Curtis
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Payne
authors.forename: Miles S
authors.initials: MS
authors.lastname: Congreve
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Wildsmith
authors.forename: Craig L
authors.initials: CL
authors.lastname: Francis
authors.forename: John E
authors.initials: JE
authors.lastname: Davies
authors.forename: Sofia I
authors.initials: SI
authors.lastname: Pascu
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Burton
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Holmes
mesh_terms: D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D004988:Ethers, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D004988:Ethers, Cyclic; C476642:obtusenyne