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New fragmentation pathways in the electron impact mass spectrometry of derivatized pyrano-1,3-diphenylprop-2-enones

✍ Scribed by Virinder S. Parmar; Sunil K. Sharma; Anand Vardhan; Rakesh K. Sharma; Jørgen Møller; Per M. Boll

Publisher
John Wiley and Sons
Year
1993
Tongue
English
Weight
287 KB
Volume
28
Category
Article
ISSN
1076-5174

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✦ Synopsis

The fragmentation patterns of closely related chalcones, cinnamoylchromans and cinnamoylchromenes, are reported to be strikingly different. The mass spectra of the first group show peaks typical of the fragmentation of simple chalcones balanced by additional fragmentation routes competing effectively with the typical chalcone fragmentation. For the other group with the introduced double bond the fragmentation is considerably changed. Initial loss of a methyl group gives rise to formation of the base peak in three of four examples. The [ M -CH, 1 + ion decomposes further, eliminating a styrene yielding the m/z 187 ion. This process may be rationalized as a retro-Diels-Alder fragmentation of a flavanone formed on intramolecular rearrangement of the molecular ion.

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