How to Interpret a Mass Spectrum Containing Ions that Undergo Rearrangement - Part 4

Butyl pentanoate undergoes a double McLafferty (like) rearrangement!


The McLafferty rearrangement, which may occur by a radical or an ionic mechanism, is observed in the gas chromatography-mass spectrometry (GC-MS) electron ionization (EI) during the dissociation of organic molecules containing a carbonyl-group and at least one γ-hydrogen atom, which involves a β-cleavage. For methyl esters, say, a fragment/product ion with an m/z = 74 is seen in the GC-MS EI spectrum.



Click to enlarge the image

M = Molecular, EE = Even-electron, OE = Odd-electron

Do you think that the above infographic offers a mass spectral data interpretation of Butyl pentanoate❓ Let Chemaficionado know at mychemistryhomework@gmail.com❗

References:

(1)    National Institute of Standards and Technology. NIST Chemistry WebBook - SRD 69. NIST. https://webbook.nist.gov/chemistry/.

(2)    Wikipedia Contributors. McLafferty rearrangement. Wikipedia.

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