Structural and conformational analysis of 1-oxaspiro[2.5]octane and 1-oxa-2-azaspiro[2.5]octane derivatives by (1) H, (13) C, and (15) N NMR.
A structural and conformational analysis of 1-oxaspiro[2.5]octane and 1-oxa-2-azaspiro[2.5]octane derivatives was performed using (1) H, (13)  C, and (15)  N NMR spectroscopy. The relative configuration and preferred conformations were determined by analyzing the homonuclear coupling constants and chemical shifts of the protons and carbon atoms in the aliphatic rings. These parameters directly reflected the steric and electronic effects of the substituent bonded to the aliphatic six-membered ring or to C3 or N2. The parameters also were sensitive to the anisotropic positions of these atoms in the three-atom ring. The preferred orientation of the exocyclic substituents directed the oxidative attack.
Unidad Académica de Ciencias Químico Biológicas y Farmacéuticas, Universidad Autónoma de Nayarit, Tepic Nayarit, México.
Rubén
R
Montalvo-González
Armando
A
Ariza-Castolo
D001388:Aziridines / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry*; D002247:Carbon Isotopes; D004852:Epoxy Compounds / Q000032:analysis* / Q000138:chemical synthesis; D005027:Ethylene Oxide / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D015394:Molecular Structure; D009587:Nitrogen Isotopes; D011522:Protons; D012015:Reference Standards; D013141:Spiro Compounds / Q000032:analysis* / Q000138:chemical synthesis; D013237:Stereoisomerism
D001388:Aziridines; D002247:Carbon Isotopes; D004852:Epoxy Compounds; D009587:Nitrogen Isotopes; D011522:Protons; D013141:Spiro Compounds; D005027:Ethylene Oxide