title: A unifying stereochemical analysis for the formation of halogenated C15-acetogenin medium-ring ethers from Laurencia species via intramolecular bromonium ion assisted epoxide ring-opening and experimental corroboration with a model epoxide.
abstract: A unifying stereochemical analysis for the formation of the constitutional isomeric halogenated C(15)-acetogenin medium-ring ether natural products from Laurencia species is presented, where an intramolecular bromonium ion assisted epoxide ring-opening reaction of enantiomerically pure epoxides can account for ring-size, the position of the halogen substituents, and relative and absolute configurations of the known natural products. Experimentally, a model epoxide corroborates the feasibility of this process for concurrent formation of 7-, 8- and 9-ring ethers corresponding to the halogenated medium-ring ethers of known metabolites from Laurencia species.
authors.affiliation: Department of Chemistry, Imperial College London, London, SW7 2AZ, UK.
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Bonney
authors.forename: D Christopher
authors.initials: DC
authors.lastname: Braddock
mesh_terms: D054378:Acetogenins / Q000737:chemistry* / Q000302:isolation & purification; D001688:Biological Products / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry* / Q000378:metabolism; D054879:Halogenation; D006219:Halogens / Q000737:chemistry* / Q000378:metabolism; D007477:Ions / Q000737:chemistry*; D044722:Laurencia / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D054378:Acetogenins; D001688:Biological Products; D004852:Epoxy Compounds; D004987:Ethers; D006219:Halogens; D007477:Ions