McLafferty rearrangement

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IUPAC RECOMMENDATIONS 2013

K. K. Murray, R. K. Boyd, M. N. Eberlin, G. J. Langley, L. Li and Y. Naito, Pure Appl. Chem., 2013, 85, 1515-1609, 10.1351/PAC-REC-06-04-06.

McLafferty rearrangement
Rearrangement reaction involving transfer of a hydrogen atom via a six-member transition state to the formal radical/charge site from a carbon atom four atoms distant from the charge/radical site (the γ-carbon); subsequent rearrangement of electron density can lead to expulsion of an olefin molecule.
Note: Originally applied to ketone molecular ions where the charge/radical site is the carbonyl oxygen, but is now more widely applied.
Related Term(s):
Reference(s):

IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the “Orange Book”). Definitive Rules, 1979. Compiled by J. Inczédy, T. Lengyel, A. M. Ure. Blackwell Scientific Publications, Oxford (1997). On-line corrected version: http://www.iupac.org /publications/analytical compendium (2000).

IUPAC. Compendium of Chemical Terminology, 2nd ed. (the “Gold Book”). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins.

Definitions of Terms Relating to Mass Spectrometry (IUPAC Recommendations 2013); DOI: 10.1351/PAC-REC-06-04-06 © IUPAC 2013.


Index of Terms

 




WIKIPEDIA ARTICLE
This term has a corresponding Wikipedia article: McLafferty rearrangement
 



Orange Book

ORANGE BOOK DEFINITION

IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the “Orange Book”). Definitive Rules, 1979.

McLafferty rearrangement

This is an example of a rearrangement reaction and is defined as β - cleavage with concomitant specific transfer of a γ - hydrogen atom in a six-membered transition state in mono-unsaturated systems, irrespective of whether the rearrangement is formulated by a radical or by an ionic mechanism and irrespective of with which fragment the charge stays.

IUPAC Orange Book Chapter 12
Index of Orange Book Terms


Gold Book

GOLD BOOK DEFINITION

IUPAC. Compendium of Chemical Terminology, 2nd ed. (the “Gold Book”). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).

McLafferty rearrangement

http://goldbook.iupac.org/M03772.html

β-Cleavage with concomitant specific transfer of a γ-hydrogen atom in a six-membered transition state in mono-unsaturated systems, irrespective of whether the rearrangement is formulated by a radical or an ionic mechanism, and irrespective of the position of the charge.

Source:

Orange Book p. 207

IUPAC Gold Book
Index of Gold Book Terms