INTERACTION OF REMOTE FUNCTIONAL-GROUPS (AMIDE AND AMINE) IN STEROIDAL COMPOUNDS AFTER ELECTRON IONIZATION

Electron impact ionization of steroidal compounds with two diferently substituted functional groups (amide and amine) at remote positions leads to the interaction of these groups in ion‐neutral complexes after the detachment of one of them. Two situations may be encountered, depending on which group is more easily detached from low‐energy parent ions: (i) when the formation of the immonium ion is preferred, a very efficient proton transfer to the amide is observed leading to abundant [M− imine]+· and subsequent daughter ions; (ii) when the detachment of the amide is preferred, hydrogen exchanges occur with the amine group, and fragment ions may be observed resulting from the addition of both groups in a proton‐bound structure. Copyright © 1990 John Wiley & Sons, Ltd.