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Regio‐specifity of the deprotonation of some aliphatic ketones and sulfones by NCl
Author(s) -
Sürig T.,
Grützmacher H.fr.
Publication year - 1989
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210240924
Subject(s) - deprotonation , chemistry , medicinal chemistry , organic chemistry , ion
The investigation of negative ions in the gas phase has found considerable interest over the last 15 years', in particular with respect to the [M-HIions of ketones and sulfones (enolate ions). Unsymmetrical ketones and sulfones with C-H bonds at both a-positions form two isomeric [M-HIions which do not isomenze in the gas phase.' For an understanding of the gas phase chemistry of these enolate ions, it is important to know the factors influencing the formation of the isomeric ions. The [M-HIions are easily generated in the gas phase by a deprotonation via chemical ionization by HO-or NH2-, and the relative abundances of the isomeric enolates in the mixture can be determined by using specifically deuterated substrates. I t has been shown for 2-pentanone-l,l,l-d3, that the H+, and D+-abstraction are observed in a statistical ratio . However, it is not known whether a statistical deprotonation will always occur during NCI and whether special kinetic or thermodynamic effects will determine the relative abundances of the isomeric [M-HI-ions. 2