抄録
Simple cleavages of protonated acetates are studied by MINDO/3. Heats of formation for two possible sites of protonation including geometrical isomers are compared; protonation at the carbnyl oxygen appears to be more stable than that at the ether oxygen in ethyl, n-propyl, and iso-propyl acetates. The difference ranges from 16 to 29 kcal/mol depending on the geometries of the protonated esters. The barrier of the interconversion between the two possible protonated structures and the potential energies of fragmentation are estimated. The results obtained were discussed in relation with the role of the proton. The optimized geometries of the protonated acetates were examined by comparing with that of ethyl acetate. The detailed organic-chemical expressions for the simple cleavages were proposed on the results of the MO calculations.
