AbstractFour dominant reactions can be observed when the β‐distonic ion·CH2CH2OH +2reacts in the cell of a Fourier‐transform ion cyclotron resonance spectrometer with a number of neutral molecules: protonation of the neutral molecule, ethylene radical‐cation transfer, hydride abstraction from the neutral molecule, and charge exchange. Among the ethylene transfer reactions, which can lead to a variety of other distonic ions, we have throroughly studied the reaction with formaldehyde. The reaction of a first molecule of CH2O yields·CH2CH2OCH +2. The addition of a second one leads to 1,3‐dioxane which stabilizes by H·loss. This latter reaction i