The Collision-Induced Dissociations of Deprotonated Isopropyl and t-Butyl Ketones. Some Unusual Alkyl Migrations

Abstract

Rearrangement reactions involving hydride and methyl anion migrations are observed when certain enolate ions derived from isopropyl and t- butyl ketones are subjected to collisional activation. For example

(i) ^-CH₂CO-i-C₃H₇ → ^-(CH₂CHO)+C₃H₆

and

(ii) ^-CH₂CO-t-C₄H₉ → ^-(CH₂COCH₃)+C₃H₆

The mechanisms of these and related reactions have been investigated by denterium labelling and product ion studies.