To test stereoelectronic control in cleavage of tetrahedral intermediates, cyclic imidatonium ions were hydrolyzed in buffered aqueous media. In carbonate buffer >97% amino ester was observed, as previously reported. However, in berate buffers 65-91% hydroxy amide was observed from five-membered-ring imidatonium ions, except for a highly alkylated one. Selectivity is attributed to leaving-group ability. Stereoelectronic control does operate in six-membered rings but provides only 2 kcal/mol toward rate acceleration. Production of amino ester in carbonate buffers is due to the bifunctional nature of bicarbonate ion and thus cannot be used to support a large stereoelectronic contribution. The geometrical requirements for bifunctional catalysis further imply the intermediacy of conformations counter to stereoelectronic control.