13C-NMR chemical shifts of substituted squalenes and model compounds with a heteroatom in d-position to a double bond show that a steric interaction exists between the hetero-atom and the double bond. This points to the presence of "precoiled" conformations in the hetero-substituted squalenes and also in squalene itself. The nature of the interaction remains veiled, but it appears to be a general feature as is shown in a series of 2- and 3-substituted thiophenes with a double bond in the side chain.
|Journal||Recueil des Travaux Chimiques des Pays-Bas|
|Publication status||Published - 1977|