Anchimeric assistance in the fragmentation of protonated glycol derivatives in a flowing afterglow

A series of monomethyl, monoacyl glycols was protonated in a flowing afterglow system. In the subsequent fragmentation reactions acetic acid was found to be a better leaving group than methanol, but the acetoxy group was shown to participate in methanol expulsion under certain conditions. The effects of leaving group ability, anchimeric assistance, stereochemistry and steric hindrance on the fragmentation patterns of the protonated molecular ions are discussed.