Base-catalyzed equilibration of anancomeric cyanocyclohexanes demonstrates that replacement of cis-3,5-dimethyl holding groups with electron-withdrawing CF3 groups dramatically increases the proportion of the axial cyano isomer present at equilibrium. The CF3… Click to show full abstract
Base-catalyzed equilibration of anancomeric cyanocyclohexanes demonstrates that replacement of cis-3,5-dimethyl holding groups with electron-withdrawing CF3 groups dramatically increases the proportion of the axial cyano isomer present at equilibrium. The CF3 groups exert an effect on the conformational energy of the cyano group worth about 0.6 kcal/mol. A nonclassical hydrogen bond between the axial CN group and the syn-axial hydrogens is a major contributor to the axial stability of the group.
               
Click one of the above tabs to view related content.