40319-81-1Relevant articles and documents
Solvolysis of 2-bicyclo[3.2.2]nonyl p-toluenesulfonate. Evidence for the formation of classical carbocation intermediates
Okazaki, Takao,Terakawa, Eiichi,Kitagawa, Toshikazu,Takeuchi, Ken'ichi
, p. 1680 - 1684 (2007/10/03)
The solvolysis rate of 2-bicyclo[3.2.2]nonyl p-toluenesulfonate (6-OTs) was nearly equal to that of cycloheptyl p-toluenesulfonate in 2,2,2- trifluoroethanol (TFE). This indicates that the ethylene bridge in 6-OTs does not significantly enhance the rate and that 6-OTs ionizes without anchimeric assistance. The solvolysis of [1-13C]-2-bicyclo[3.2.2]nonyl p- toluenesulfonate in methanol or TFE gave 2-substituted bicyclo[3.2.2]nonane, exo-2-substituted bicyclo[3.3.1]nonane, 2-bicyclo[3.22]nonene (10), and 2- bicyclo[3.3.1]nonene (11), whose distributions of 13C labels were determined by quantitative 13C NMR analysis using a relaxation reagent. The 13C labels were exclusively placed at only two positions, the ratios of them were not unity, and the labels in 10 were less extensively scrambled than those in other products. These results indicate that the 2- bicyclo[3.2.2]nonyl cation is classical and that 10 is formed at a former ionization stage than 2-substituted bicyclo[3.2.2]nonane. The 13C redistributions for both exo-2-substituted bicyclo[3.3.1]nonane and 11, which are yielded via 1,3-hydride shift, were similar to that of 2-substituted bicyclo[3.2.2]nonane, suggesting that 1,3-hydride shift occurs mainly at the solvent-separated ion pair.
