title: (1)H, (13)C NMR and X-ray crystallographic studies of highly polyhalogenated derivatives of costunolide lactone.
abstract: The costunolide lactone, a sesquiterpene compound isolated from Zaluzania triiloba species, reacted with several dihalocarbene sources produced by trihaloform-NaOH under successive phase transfer reactions yielding mono-, bis- and tris-dihalocyclopropane adducts. The structures, as well as the configurational assignments of the different derivatives, were established by (1)H and (13)C NMR spectroscopy and assisted by X-ray crystallographic and molecular modelling studies. The specific shielding of protons in the neighbourhood of different halogens on the cyclopropane moieties was correlated to the pseudocontact interactions.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, C.U. Coyoacán, 04510 México D.F., Mexico.
authors.forename: D
authors.initials: D
authors.lastname: Corona
authors.forename: E
authors.initials: E
authors.lastname: Díaz
authors.forename: J L
authors.initials: JL
authors.lastname: Nava
authors.forename: A
authors.initials: A
authors.lastname: Guzmán
authors.forename: H
authors.initials: H
authors.lastname: Barrios
authors.forename: A
authors.initials: A
authors.lastname: Fuentes
authors.forename: S A
authors.initials: SA
authors.lastname: Hernandez-Plata
authors.forename: J
authors.initials: J
authors.lastname: Allard
authors.forename: C K
authors.initials: CK
authors.lastname: Jankowski
mesh_terms: D000871:Anthelmintics / Q000737:chemistry; D002247:Carbon Isotopes; D018360:Crystallography, X-Ray / Q000379:methods*; D006219:Halogens; D007783:Lactones / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D012717:Sesquiterpenes / Q000737:chemistry*
chemical_list: D000871:Anthelmintics; D002247:Carbon Isotopes; D006219:Halogens; D007783:Lactones; D012717:Sesquiterpenes; C002602:costunolide