2.3- Dimethylpentane mass spectrum

Mass spectrum of 2,4-dimethylpentane, given both as a bar graph and in tabular form. Abundances are given as percentages of the strongest peak (the base peak). In this example, the base peak is at m/z 41 and the molecular ion peak (parent peak) is at m/z 100. Notice that the molecular ion has an even mass number, while most of the fragments are odd. 

Show the fragmentations that give rise to the peaks at m/z 43, 57, and 85 in the mass spectrum of 2,4-dimethylpentane (Figure 12-16). 

The mass spectrum of 2,3-dimethylpentane also shows peaks at m/z = 57 and 43. Propose possible stmctures for the ions that give rise to these peaks. 

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