Rate and Product Studies with 2-Methyl-2-Chloroadamantane under Solvolytic Conditions

Reactions of 2-methyl-2-chloroadamantane (1) in a variety of pure and binary solvents have been studied at various temperatures and pressures up to 80 MPa. The sensitivity (m) to changes in solvent ionizing power of the Grunwald-Winstein equation, and the activation volume (Delta V(double dagger)) are calculated from the specific rates. An excellent linear relationship (R = 0.997) for 1, log (k/k(0))= 0.80Y(Cl) + 0.11, and the activation volume, Delta V(double dagger) = -15.2 similar to-10.2 mL.mol(-1) were observed. These values are similar to those for solvolyses of 1-adamantyl halides over the full range of solvents, suggesting that the unimolecular mechanism involving ion pairs is rate-determining. These observations arc also compared with those previously reported for the corresponding 1-adamantyl derivatives and chloroformate esters.This paper was supported by Korean Council for University Education, grant funded by Korean Government (MOEHRD) for 2008 Domestic Faculty Exchange