Transposition des Cycles Satures en Spectrometrie de Masse IV—Dioxolanes Derives de Cetones a Cycle Moyen et Grand

The fragmetation mechanism of cyclanone ethylene acetals in the medium ring and macrocyclic series has been re-investigated. The fragmentation pattern can be explained entirely on the basis of a new rearrangement, involving a ring contraction and hydrogen migrations, which have been checked by using deuterated compounds.