J. B. Lambert, R. W. Emblidge, Yan Zhao
Sep 1, 1994
Citations
0
Influential Citations
10
Citations
Journal
Journal of Organic Chemistry
Abstract
Diethyl (2-(tosyloxy)cyclohexyl)phosphonates have been prepared to test the hypothesis that the strongly electron-withdrawing phosphonate group can stabilize the formation of a β carbocation through hyperconjugation. Systems were constructed with the 180 o dihedral angle between phos- phonate and tosyloxy that is optimal for such participation and with the 60 o dihedral angle that minimizes it. Reactions were carried out in aqueous mixtures of ethanol, trifluoroethanol, and hexafluoro-2-pro- panol. The 60 o case had the standard profile for bimolecular reaction with solvent (k s ), with a slower rate that is sensitive to solvent nucleophilicity