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Carbon‐13 magnetic resonance study of spiro compounds
Author(s) -
Zimmermann D.,
Ottinger R.,
Reisse J.,
Christol H.,
Brugidou J.
Publication year - 1974
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270060610
Subject(s) - cyclopentane , substituent , cyclohexane , paramagnetism , diamagnetism , ring (chemistry) , chemistry , carbon atom , carbon fibers , ring size , carbon 13 , crystallography , nuclear magnetic resonance , stereochemistry , organic chemistry , materials science , physics , magnetic field , condensed matter physics , quantum mechanics , composite number , composite material
A large series of cyclohexane and cyclopentane spiro compounds has been studied by carbon‐13 NMR. Increments have been derived in terms of α, β, γ spiro substituent effects, one ring being considered as the substituent of the other. As usual α and β effects are paramagnetic and γ effects are diamagnetic. They are compared with the corresponding effects associated with the introduction of a gem dimethyl group into a cyclohexane or cyclopentane ring. The size of the two rings involved in the spirane structure has a marked influence especially on the chemical shift of the spirane carbon atom. Comparison between monospiro and dispiro derivatives gives information about the so‐called 1,5 or δ effect which is paramagnetic. From an analytical point of view, carbon‐13 NMR appears to be a powerful method of detecting the spirane structure, apparently including the relative size of the rings.