CHARGE-REMOTE FRAGMENTATION AND THE 2-STEP ELIMINATION OF ALKANOLS FROM FAST ATOM BOMBARDMENT-DESORBED (M-H)- IONS OF AROMATIC BETA-HYDROXYOXIMES(H)+, (M+CAT)+, AND (M)

Aromatic beta-hydroxyoximes undergo unusual fragmentation reactions as protonated or cationized species, as radical cations, or as (M - H)- ions. As protonated species, they expel OH. from the oxime functionali ty in violation of the even electron rule. Parallel eliminations of al kyl radicals follow OH' loss when the aromatic ring is substituted wit h an alkyl chain. Alkyl radical losses appear to be characteristic of radical cations that can isomerize to ions in which the alkyl chain be ars a radical site and the charged site is the conjugate acid of a bas ic functionality (e.g., oxime or imine). Evidence for the mechanisms w as found in the ion chemistry of oxime and imine radical cations. The imine reference compounds were conveniently generated by fast atom bom bardment-induced reduction of oximes, removing the requirement for usi ng conventional chemical synthesis. Protonated imines and the (M - H)- ions of oximes fragment extensively via charge-remote processes to eli minate the elements of alkanes. This chemistry is not shared by the pr otonated oximes.