Résonance Magnétique Nucléaire de 17O. Aldéhydes et cétones aliphatiques: additivité des effets de substitution et corrélation avec la 13C‐RMN

17O‐NMR. Aliphatic aldehydes and ketones, additivity of substituent effects and correlation with 13C‐NMR. The 17O‐chemical shifts of 9 aldehydes, 22 aliphatic and 4 alicyclic ketones, in the natural abundance FT.‐NMR. spectra followed a good correlation with the 13C‐chemical shifts of the terminal C‐atoms of corresponding methylene compounds. An additivity relation involving 6 parameters represents the 17O‐shifts of 28 of the measured products with a standard deviation of 2.5 ppm. The additivity parameters are discussed with respect to the modifications of the polarity of the carbonyl group induced by the hyperconjugative interaction of π and π* orbitals with the πCH3 orbitals of the alkyl substituent groups.