Studies in mass spectrometry. Part XXI. Migrations to carbonium ion centres generated upon electron impact

Abstract

Skeletal rearrangement reactions induced by electron impact have been studied in a number of halogeno-esters, halogeno-acids, and related compounds. It is found that the generation of a carbonium ion in the mass spectrometer, by loss of a chlorine or bromine radical from a molecular ion, is frequently followed by migration of a methoxy- or hydroxy-group (in the case of methyl esters or acids) to the carbonium-ion centre. As a result combinations of atoms are generated which are not present as structural units in the original molecule.