DO CARBANIONS UNDERGO 1,2-HYDROGEN TRANSFERS IN THE GAS-PHASE

Certain anions X-(CH)-C---CH2-Y and X-CH2-(CH)-C---Y interconvert unde r collisional activation conditions in the gas phase, Experiments desi gned to probe the mechanism(s) of particular interconversions suggest (i) that the ions MeO-CH2-(CH)-C---CN and MeO-(CH)-C---CH2-CN intercon vert via 1,2 H transfer processes, and (ii) when X = Ph and Y = CO(2)M e or CN, deuterium labelling and fragmentation data indicate that equi libration of Ph-(CHCH2Y)-C-- and PhCH(2)-(CHY)-C-- occurs, at least in part, by proton transfer to and from the phenyl ring.