Cleavage of the Allylic Bond in Aliphatic Alkenes

As hydrogen rearrangements prior to dissociation are prevalent in alkene molecular ions, the radical site migrates along the chain, thereby obscuring the original location of the double bond [55]. H- and C-labeling revealed that the mo- 

Note Extensive isomerization prior to or between single steps of fragmentation makes the mass spectra of isomeric alkenes become very similar. 

Example The spectra of 1-decene, ( )-5-decene, and (Z)-5-decene are shown below (Fig. 6.17). Whereas in the spectrum of 1-decene the basepeak at m/z 41 can easily be explained as a result of allylic cleavage, the base peak of both 

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