The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

Author(s):

Yang Mingyan, Wang Daoquan and Wang Mingan*   Pages 1139 - 1147 ( 9 )

Abstract:

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

Keywords:

2-Phenylcyclododecanone, 2-cyclohexylcyclododecanone, [3333]-2-one conformation, π-π electron effect, conformation analysis, conformation control.

Affiliation:

Department of Applied Chemistry, China Agricultural University, Beijing 100193, Department of Applied Chemistry, China Agricultural University, Beijing 100193, Department of Applied Chemistry, China Agricultural University, Beijing 100193

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