ACETOLYSIS OF TRANS-2-TOSYLOXYCYCLOHEXYL-SUBSTITUTED BENZOATES - KINETICS AND OXYGEN-18 STUDIES

Ten 2-tosyloxycyclohexyl benzoates containing various substituents in the meta and para positions of the benzoyl group were solvolyzed at 97.7° in anhydrous acetic acid containing acetate ions. In addition four of these compounds were solvolyzed at 90.2 and 103.7° in the same reaction medium. Acetolysis was also conducted on three of these compounds which were labeled with oxygen-18 on the carbonyl oxygen. There is excellent correlation between the rates of acetolysis and the Hammett polar substituents σ. Several compounds, whose rates were measured at three different temperatures, provided the data necessary for calculating the entropies, enthalpies, and free energies of activation reported herein. Acetolysis of several compounds with oxygen-18 enrichment in the carbonyl oxygen led to the incorporation of the oxygen-18 in the cyclohexanediol. These results are consistent with reaction pathway that proceeds via a symmetrical benzoxonium ion intermediate. © 1969, American Chemical Society. All rights reserved.