Ren and Yamataka have shown from G2(+) model chemistry that gas phase (GP) alpha-effects of approximately 4-6 kJ/mol energy difference are probable. We have investigated GP alpha effects for hydroxide and hydroperoxide attacking methylformate, a system recently explored by DePuy via flowing afterglow experiments. Through careful benchmarking against these experiments, we determined that the HF/6-311+G(2df,2p) level of theory is best for reproducing DePuy's experimentally measured reactivity ratio for methyl abstraction. Our results closely approximate the Ren and Yamataka results at a much lower computational cost. The results allow explanations of several features of reactivity and comparison with other systems of nucleophiles.