The Fragmentation Mechanism of Cyclobutanol

The mass spectra of cyclobutanol and three 2 H labelled analogs have been studied. The losses of C 2 H 4 and C 2 H 5 * from the molecular ion involve specific fragmentations. Only CH 3 * loss from the α-cleaved molecular ion 2 clearly involves hydrogen atom scrambling; this fragmentation also proceeds by a specific mechanism involving C-2 and hydroxyl hydrogen atoms. Loss of water from the molecular ion involves all the hydrogen atoms but in a complex, non-random manner.