Metal ion effects on the rate of intramolecular O-alkylation of the anion of ethyl(3-chloropropyl)acetoacetate

Article abstract of DOI:10.1016/S0040-4020(01)86699-0

The retarding effect of alkali metal and alkaline-earth metal ions on the rate of intramolecular O-alkylation of the title compound has been thoroughly investigated in 99% aqueous Me₂SO at 25°C. Rate data have been dissected into contributions of free ions (k_i) and ion pairs (k_ip). Comparison of the present results with available data for intramolecular C-alkylation of a strictly related system, reveals that rate-depressing effects due to cation pairing turn out to be remarkably similar in the two processes, which is at variance with the expectation of a more pronounced cation dependence of the k_ip/k_i ratios for O-alkylation than for C-alkylation.