Electrospray ionization of methanolic solutions of p-hydroxyphenacyl derivatives HO-C 6 H 4 -C(O)-CH 2 -X (X = leaving group) provides abundant signals for the deprotonated species which are assigned to the corresponding phenolate anions − O-C 6 H 4 -C(O)-CH 2 -X. Upon collisional activation in the gas phase, these anions inter alia undergo loss of a neutral "C 8 H 6 O 2 " species concomitant with formation of the corresponding anions X − . The energies required for the loss of neutral roughly correlate with the gas phase acidities of the conjugate acids (HX). Extensive theoretical studies performed for X = CF 3 COO in order to reveal the energetically most favorable pathway for the formation of neutral "C 8 H 6 O 2 " suggest three different routes of similar energy demands, involving a spirocyclopropanone, epoxide formation, and a diradical, respectively.