(1)H, (13)C NMR and X-ray crystallographic studies of highly polyhalogenated derivatives of costunolide lactone.
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.
Corona
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Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, C.U. Coyoacán, 04510 México D.F., Mexico.
Díaz
E
E
Nava
J L
JL
Guzmán
A
A
Barrios
H
H
Fuentes
A
A
Hernandez-Plata
S A
SA
Allard
J
J
Jankowski
C K
CK
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*
D000871:Anthelmintics; D002247:Carbon Isotopes; D006219:Halogens; D007783:Lactones; D012717:Sesquiterpenes; C002602:costunolide