1- Methyl-1-cyclohexyl cations conformations

Other recent applications include, for instance, the methyl-cyclohexyl cation (9), which can adopt two different chair conformations characterized by CC and CH hyperconjugation, respectively, and the cyclopropylidenvinyl-cyclopropylmethyl cation (lO), the NMR spectrum of which could be assigned on the basis of highly accurate GIAO-CCSD(T) chemical shifts. 

Hyperconjugation has a profound effect on structure and stability of cyclohexyl cations. An elegant study combined theoretical results with experimental data to confirm that different hyperconjugative stabilization patterns lead to the formation of two equilibrating conformers of the 1-methyl-1-cyclohexyl cation where the carbocation p-orbital is oriented either pseudoaxiaUy or pseudoequatoriaUy. 

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