Rate and Product Studies of 1-Adamantylmethyl Haloformates Under Solvolytic Conditions

Reactions of 1-adamantylmethyl chloroformate (1-AdCH(2)OCOCl, 1) and 1-adamantylmethyl fluoroformate (1-AdCH(2)OCOF, 2) in hydroxylic solvents have been studied. Application of the extended Grunwald-Winstein (G-W) equation to solvolyses of 1 in a variety of pure and binary solvents indicates an addition-elimination pathway in the majority of the solvents except an ionization pathway in the solvents of relatively low nucleophilcity and high ionizing power. The solvolyses of 2 show an addition-elimination pathway in all of the mixed solvents. The leaving group effects (k(F)/k(Cl)), the kinetic solvent isotope effects (KSIEs, k(MeOH)/k(MeOD)), and the enthalpy and entropy of activation for the solvolyses of! and 2 were also calculated. The selectivity values (5) for each solvent composition are reported and discussed. These observations are compared with those previously reported for other alkyl haloformate esters.