Stereoisomeric effects on mass spectral fragmentations of chloronorbornanones

✍ Scribed by A. P. Rothwell; R. G. Cooks; T.-V. Singh; L. De Cárdenas; H. Morrison

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 574 KB
• Volume: 20
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210201212

✦ Synopsis

Stereoelectronic factors allow facile CI' atom loss from the ero-6-chloro-2-norbornanone radical cation but not from the endo-6-epimer. The predominant primary reaction in the endo-6 and in the m o d and endo-5 compounds is HCI elimination. While C1' e l i n a t i o n occurs with skeletal reorganization, HCI loss, at least in part, does not. The 5-chloro isomers undergo a regiospecific McLafferty rearrangement which occurs relatively slowly in competition with CI' and HCI loss. The use of energy-resolved forms of tandem mass spectrometry provides considerable detail regarding the unimolecular fragmentations of these gaseous ions.