METAL-ION EFFECTS ON THE RATE OF INTRAMOLECULAR O-ALKYLATION OF THE ANION OF ETHYL(3-CHLOROPROPYL)ACETOACETATE

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 (ki) and ion pairs (kip). 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 kip/ki ratios for O-alkylation than for C-alkylation. © 1990.