Chemical ionization mass spectrometry of crown ether acetals using isobutane as reagent gas

Abstract

Abstract Isobutane chemical ionization mass spectrometry of crown ether acetals (M), derived from ethanal, give [MH] + ions from which species corresponding to 44 u are successively eliminated. Mechanisms are presented in which these units correspond to (i) ethanal and (ii) oxirane. An accompanying process is the elimination of ethyne. Similar reactions occur in the chemical ionization mass spectrometry of benzo crown ether acetals.