Analyses of Carbon-13 Nuclear Magnetic Resonance Spectra ofIsopropyldibenzofurans and Their Structural Determinations

Genki TAKEUCHI, Hiroshi OKAZAKI, Taketoshi KITO, Yoshio KOSUGI
1991 Analytical Sciences  
Carbon-13 NMR spectra of isomers of four mono-and three diisopropyldibenzofurans were recorded by an NMR spectrometer with a magnet of 9.4 T (or 400 MHz type). Even if the sample was a mixture of components or was of only 50% purity, unequivocal assignments were obtained by means of carbon-proton correlated spectroscopy (C-H COSY). Based on the a-effect by isopropyl group, and with the assistance of quaternary spectra (QUAT), one of diisop.ropyldibenzofurans was determined to be 2,4-isomer, and
more » ... be 2,4-isomer, and not 1,3-isomer which can not be ruled out by 'H NMR . The chemical shifts of the isopropyl groups are more dependent on substituent positions in 13C than in 'H NMR spectra . All 36 possible kinds of isopropyldibenzofurans are distinguishable using the present results together with ' H NMR data. Keywords Carbon-13 nuclear magnetic resonance, isopropyldibenzofuran,
doi:10.2116/analsci.7.843 fatcat:xnaf7jwzkfei7jo7eorpadx7na