What is mclafferty rearrangement?

McLafferty rearrangement is a fragmentation reaction that occurs in mass spectrometry. It involves the loss of a neutral molecule from a molecular ion, resulting in the formation of a characteristic rearranged fragment ion.

The rearrangement typically occurs in molecules containing a carbonyl group (such as ketones, aldehydes, esters, and amides) and a neighboring alpha hydrogen atom. The process involves the migration of a hydrogen atom from the alpha position to the oxygen atom of the carbonyl group, followed by the cleavage of a bond adjacent to the carbonyl group, resulting in the loss of a neutral molecule.

McLafferty rearrangement is commonly observed in electron impact ionization mass spectrometry, where it can provide valuable information about the structure of a molecule by generating structurally informative fragment ions. The rearranged fragment ions can help in identifying the functional groups present in a molecule and can aid in determining its chemical structure.

Overall, McLafferty rearrangement is a useful tool in mass spectrometry for the structural elucidation of complex organic molecules.