1H, 1 3C, and 1 5N Chemical shifts and 1H-1 5N and 1 3C-1 5N heteronuclear spin-spin coupling constants in the NMR spectra of 5-substituted furfural oximes

摘要: The 1H, 13C, and 15N NMR spectra of 15N-enriched 5-substituted furfural oximes were investigated. It was shown that the chemical shifts ring atoms oxime group correlate satisfactorily with F R substituent constants, whereas their sensitivity to effect substituents is lower than in monosubstituted furan derivatives. constants spin-spin coupling between protons determined. An analysis 1H-1H (SSCC) on basis stereospecificity indicates E isomers have primarily an s-trans conformation polar dimethyl sulfoxide, Z isomers, other hand, s-cis conformation. signs direct geminal 13C-15N SSCC determined for 5-trimethylsilylfurfural oxime.