Abstract: The ring size (n) range for the quantitative investigation of the lactonization of w- bromoalkanoic acids with strong bases in 99% aqueous MezSO has been considerably extended by the determination of the rate constants for several large rings (n= 13-1 6, 18, and 23) and for n= 3. Also activation parameters have been determined for all the compounds studied so far in the range between 7 and 23 and for n= 3. The three- ...