title: A biosynthetically-inspired synthesis of the tetrahydrofuran core of obtusallenes II and IV.
abstract: [reaction: see text] Sharpless asymmetric dihydroxylation was regioselective for the trans olefin in an E vs Z vs terminal triene substrate. To test a biosynthetic hypothesis, the resulting diol underwent diastereoselective bromoetherification to provide the des-chloro core of marine natural products obtusallenes II and IV. Alternatively, anionic chloride ring-opening of a Z-beta,gamma-unsaturated epoxide gave separable regioisomeric halohydrins. Bromoetherification gave the fully elaborated core of obtusallenes II and IV with all of the relative stereochemistry correctly set.
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K. c.braddock@imperial.ac.uk
authors.forename: D Christopher
authors.initials: DC
authors.lastname: Braddock
authors.forename: Roshni
authors.initials: R
authors.lastname: Bhuva
authors.forename: David S
authors.initials: DS
authors.lastname: Millan
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Pérez-Fuertes
authors.forename: Craig A
authors.initials: CA
authors.lastname: Roberts
authors.forename: Richard N
authors.initials: RN
authors.lastname: Sheppard
authors.forename: Savade
authors.initials: S
authors.lastname: Solanki
authors.forename: Elaine S E
authors.initials: ES
authors.lastname: Stokes
authors.forename: Andrew J P
authors.initials: AJ
authors.lastname: White
mesh_terms: D001688:Biological Products / Q000737:chemistry*; D001966:Bromine / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D004987:Ethers / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis*; D006900:Hydroxylation; D044722:Laurencia / Q000737:chemistry*; D008386:Marine Biology; D008956:Models, Chemical; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D004852:Epoxy Compounds; D004987:Ethers; D005663:Furans; C018674:tetrahydrofuran; D001966:Bromine