Mechanism of the expulsion of oh from the [M - C2H4]+˙ ion from ethyl benzoate

Abstract
Ion kinetic energy spectra of the esters C6H5C18OOC2D5 and C6H5COOC2D5 show that the ion formed by loss of C2D4 from the molecular ion has the deuterium atom attached to the carbonyl oxygen atom. Transfer of this deuterium to the other oxygen can only take place via exchange reactions involving the ortho‐hydrogen atoms and requires at least two complete rotations of the side‐chain.