Pericyclic reactions. Part I. An examination of some potentially pericyclic reactions in the mass spectrometer

Abstract

An examination of several compounds which might show pericyclic fragmentations in the mass spectrometer was undertaken in the hope of finding out whether ground or excited electronic states were involved. The compounds examined showed both photochemically ‘allowed’ and thermally ‘allowed’ reactions and it is concluded that the Woodward–Hoffmann rules for pericyclic reactions are, at the present state of knowledge, a poor probe into the energy levels occupied by ions fragmenting in the mass spectrometer.