Studies in organic mass spectrometry—VI. The fragmentation of enol derivatives of acyclic β‐diketones

The mass spectra of enol derivatives of β‐diketones, such as enol ethers and enaminies are discussed. Their behaviour under electron‐impact is in accordance with the fragmentation we suggested for an acyclic β‐diketone in the enol form. Rearrangement of the enol functional group is observed in the spectra. This process is a general one, as it show not only migration of oxygen and nitrogen in the enol ethers and enamines, but also migeration of sulphur and chlorine in the thio‐ether and in 4‐chloro‐3‐pentene‐2‐one. Enol derivatives are suitable compounds for determining the branching of alkyl chains in β‐diketones.