Isomerisation reactions of β-ethyl anions in the gas phase
Abstract
Evidence based primarily on the technique of collisional activation mass spectrometry is presented which suggests that substituted β-ethyl anions (XCH2CH2–) are at best transient species in the gas phase often rearranging to more stable isomers, e.g., MeCOCH2CH2–→ MeCOCHMe, PhCOCH2CH2–→ PhCOCHMe, HOCOCH2CH2–→ MeCH2CO2– and CH2CHCH2CH2→–CH2–CHCH–Me. The β-methoxycarbonylethyl anion MeOCOCH2CH2– is presumably unstable with respect to its radical since no peak corresponding to either this species or a stable isomer is observed.