A search for a β effect: the nucleophilicity of the methylene glycolate anion

The possible existence of a β-effect (effect of a lone pair of electrons located at a β position of a nucleophile) was investigated by reacting méthyléne glycolate anion with p-nitrophenyl acetate, 2,4-dinitro-fluorobenzene and 2,4-dinitrochlorobenzene in water. For these reactions, no enhanced nucleophile reactivity was found. An upper limit of 2.5 was found for the nucleophilicity n of méthyléne glycolate on the Swain-Scott scale and 6.2±0.2 on Ritchie's N₊ scale.