Alkyl and Aryl Esters of Arenesulfonic Acids

No rearrangement processes appeared to take place in the relatively simple 80 eV mass spectra of aryl tosylates 63a-e46, characterized by (a) distinct molecular ions (b) base peaks at m/z 91, except for 63e which showed an ion corresponding to [ArO] + as the most intense peak (c) fragmentation routes initiated by S—O bond fission to give the [ArO] + ion, favored by electron-donating substituents (equation 17). 

The mass spectra of arylsulfonylmethyl arenesulfonates and arylsulfonylmethyl tri-fluoromethanesulfonates have been discussed47 and reviewed6. Their fragmentation patterns were typical of those of the two functionalities, sulfone and sulfonate, plus an additional fragmentation mode, yielding abundant [M — CH20] + ions. 

The positive- and negative-ion mass spectra of ethyl benzenesulfonate have been reported48. In the positive-ion mode, the parent radical cation either eliminated ethyl radical and neutral S02 sequentially or rearranged with loss of S02, formally yielding the radical cation of phenol. In the negative-ion mode, the molecular anion underwent loss of C6H5 or C2HsO. 

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