Tetrahedron

Spiranes—IV: Long range shielding effects by benzene, thiophene and furan rings in the proton magnetic resonance spectra of diarylspiroketones

HAP De Jongh, H Wynberg

Index: de Jongh,H.A.P.; Wynberg,H. Tetrahedron, 1965 , vol. 21, p. 515 - 533

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Citation Number: 35

Abstract

The proton NMR spectra of several diphenyl, dithienyl and difurylspiroketones have been analysed and compared with the spectra of the analogous spiroketones without aryl groups. The comparison reveals that the two benzene, thiophene and furan rings in the diarylspiroketones exert a strong shielding effect upon protons at distances of 3–4 Å from the aryl rings. The effect is most marked in the diphenylspiroketones B, E and G, in which the ...