
%0 Journal Article
%A Currie, GJ 
%A Stringer, MB 
%A Bowie, JH 
%A Holmes, JL 
%T Collision-Induced Carbanion Rearrangements. The Elimination of Ethene From the 3,3-Dimethylheptan-4-one Enolate Ion
%J Australian Journal of Chemistry
%D 1987/08/01
%V 40
%N 8
%P 1365-1373
%K 
%R https://doi.org/10.1071/CH9871365
%U https://www.publish.csiro.au/paper/CH9871365 
%X The mechanisms of formation of the major product ions produced by collision activation of the enolate negative ion of 3,3-dimethylheptan-4-one have been studied by deuterium labelling. H2 loss involves 1,2-elimination from the 6- and 7-positions. Methane elimination is complex involving three competitive rearrangement processes. Ethene loss produces the most abundant fragment ion and occurs by elimination of the C1-C2 ethyl group with concomitant proton transfer from the 1-position. In the case of the enolate ion from CD3CH2CMe2COPr, the expected elimination of C2H2D2 competes with loss of C2H4 from positions 6 and 7. Other decompositions are as follows: loss of C3H8 involves the methyl and ethyl substituents at positions 7, 1 and 2 respectively; loss of C4H8 occurs by two processes, ( i ) successive losses of two C2H4 units (from the 1, 2 then 6, 7 positions), and (ii) loss of CH2=CMe2 (from the 2 and 3 positions); and loss of C5H12 produces Et-C=C-0-.  . 
