TY - JOUR
T1 - Cycloalkene budding
T2 - Mass spectrometric studies of competitive and dual cycloalkene extrusion reactions from doubly unsaturated aldehyde N, N- dimethylhydrazones
AU - Weibel, Douglas B.
AU - Attygalle, Athula B.
AU - Shevy, Laura E.
AU - Meinwald, Jerrold
PY - 2000
Y1 - 2000
N2 - Mass spectral fragmentation pathways of four doubly unsaturated aldehyde N, N-dimethylhydrazones were investigated using EI-MS and tandem mass spectrometry (MS/MS) under electron ionization and collisionally activated decomposition (CAD) conditions. Cyclopentene extrusion was found to be slightly favored over cyclohexene loss in a hydrazone capable of losing either cycloalkene. Evidence for the regeneration of a chain-shortened iminium radical cation as a result of cycloalkene extrusion was provided by studying substrates capable of undergoing successive cycloalkene budding sequences. EI-MS of these compounds shows sequential loss of both cyclopentene and cyclohexene, in accord with expectations for a cascade mechanism. Although these MS/MS experimental results are also compatible with alternative mechanisms which would entail the simultaneous loss of both neutral cycloalkenes or of a macrocyclic diene, a rapid cascade of cycloalkene budding accounts best for the experimental observations. Copyright (C) 2000 John Wiley and Sons, Ltd.
AB - Mass spectral fragmentation pathways of four doubly unsaturated aldehyde N, N-dimethylhydrazones were investigated using EI-MS and tandem mass spectrometry (MS/MS) under electron ionization and collisionally activated decomposition (CAD) conditions. Cyclopentene extrusion was found to be slightly favored over cyclohexene loss in a hydrazone capable of losing either cycloalkene. Evidence for the regeneration of a chain-shortened iminium radical cation as a result of cycloalkene extrusion was provided by studying substrates capable of undergoing successive cycloalkene budding sequences. EI-MS of these compounds shows sequential loss of both cyclopentene and cyclohexene, in accord with expectations for a cascade mechanism. Although these MS/MS experimental results are also compatible with alternative mechanisms which would entail the simultaneous loss of both neutral cycloalkenes or of a macrocyclic diene, a rapid cascade of cycloalkene budding accounts best for the experimental observations. Copyright (C) 2000 John Wiley and Sons, Ltd.
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U2 - 10.1002/1097-0231(20000715)14:13<1105::AID-RCM993>3.0.CO;2-B
DO - 10.1002/1097-0231(20000715)14:13<1105::AID-RCM993>3.0.CO;2-B
M3 - Article
C2 - 10867684
AN - SCOPUS:0033921933
SN - 0951-4198
VL - 14
SP - 1105
EP - 1109
JO - Rapid Communications in Mass Spectrometry
JF - Rapid Communications in Mass Spectrometry
IS - 13
ER -