Studies in mass spectrometry—XX : Bond-forming reactions occurring in the fragmentation of some α,β-unsaturated esters and nitriles upon electron impact

✍ Scribed by D.H. Williams; R.G. Cooks; J.H. Bowie; P. Madsen; G. Schroll; Sven-Olov Lawesson

• Publisher: Elsevier Science
• Year: 1967
• Tongue: French
• Weight: 487 KB
• Volume: 23
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)83373-1

✦ Synopsis

Abetrac-Bond-forming reactions which occur in the decomposition of mne a&unsaturated eaten and nit&a upon electron impact are dcacribed. The reactions include bond formation between adjacent phenyl and cyanide substitucnts in structurea of type A, and alkoxyl (or hydroxyl) migrations (probably by 1,3+hifts) in systems of type B, to give ions rqmxented by C. A previously dwcrii cyclization reaction is shown to facilitate the expbion of an ortbsubstituent (at the site of cycli72tion) in a phenyl ring relative to the corresponding metaand pora-substitumts. C&CiR+oR' R(R'G=CKKO,Rn R&-OR" A B C REACXONS oamring

upon electron impact which necessitate bond formation between two atoms X and Y, where neither X nor Y is hydrogen, are of both practical and mechanistic interest. A recent review ark19 has summarized such reactions which have hitherto been reported. The present paper deals with some novel migrations of functional groups which are evident from the mass spectra of a variety of a$unsaturated nitriles and esters, represented in general by the structures I-IV.