Ab initio studies on reaction H2C=C(OH)Li+CH3 + (CH3 -)

The possible structures and isomerizations of H2C=C(OH)Li are studied theoretically by the gradient analytical method at RHF/6-31+G level. According to these results, reactions of H2C=C(OH)Li with CH3 + and CH 3 - are investigated thoroughly. When H2C=C(OH)Li reacts with CH 3 + , HzC=C(OH)Li firstly changes from structure1 to structure4, and then combines with CH3 +. In this reaction, the configuration of central carbon is retained. When H2C=C(OH)Li reacts with CH 3 - , structure1 firstly breaks its C-O bond to give contact ion-pair. Then through transition state16 which is similar to structure2, the attack of CH 3 - from the opposite side of-OH replaces-OH group and inverts the configuration of carbenoid carbon atom. All the results show that the ambident reactivity of carbenoid has close relationship with the stability of special structures.