Enthalpy and entropy in ring closure reactions

The strain and entropy effects of the lactone formation from omega-bromoalk ane-carboxylate ions in ring sizes 3 to 23 is reevaluated. We find that Del ta H double dagger is the largest contributor to the observed rates (Delta G double dagger) for ring sizes 3 to 6, while -T Delta S double dagger has little influence, -T Delta S double dagger has more effect on the observed rates for ring sizes 8 and larger. (C) 1998 Academic Press.