Fragmentation and mass spectra of Esters

• Molecular ion peak is weak but noticeable.
• The most characteristic peak results from McLafferty rearrangement. 
  
• Other important Peaks results from bond cleavage next to C=O.
  
• gives an easily recognizable peak for esters.
• Easters, in which the acid portion is the predominant portion of molecule, the fragmentation pattern is same as described for the fragmentation pattern of free acid.
  
• Easters, in which the alcohol portion is the predominant portion of molecule, eliminate a molecule of acid on fragmentation.
• lets check spectrum of methyl octanoate