LIMITATIONS OF THE TRANSITION STATE VARIATION MODEL. II, DUAL REACTION CHANNELS FOR SOLVOLYSES OF 2,4,6-TRIMETHYLBENZENESULPHONYL CHLORIDE

Rate constants for solvolyses of 2,4,6-trimethylbenzenesulphonyl chloride are reported for aqueous binary mixtures with acetone, acetonitrile, dioxane, ethanol and methanol. Kinetic solvent isotope effects in water and in methanol and product selectivities in alcohol-water mixtures are also reported. Hence, in agreement with an earlier consensus, neither of the reaction channels corresponds to an S N 1 mechanism. From the kinetic solvent isotope effect of 1.68 in methanol, it is proposed that the reaction channel favoured in less polar media is general-base catalysed and/or is possibly an addition-elimination pathway