The reactions CH3+ + CH2=CNa(OH) --> CH2=C(CH3)(OH) + Na+ and CH3- + CH2=CNa(OH) --> CH2= C(CH3)Na + OH- have been investigated at the RHF/G-31+G* ab initio level of theory. The electron correlation contributions were evaluated at the MP2(fu)/6-31+G* level of theory at the RHF/6-31+G* optimized structures. The first reaction needs CH2=CNa(OH) to change from three-member-ring 1 to nonplanar structure 1, and the carbenoid mechanism does not work. The second reaction has a planar transition state similar to the metal-stabilized carbenium 2, and this transition state indicates that the "rnetal-assisted ionization" mechanism is likely to happen.