A Mechanistic Study of Hydroxide Anion Addition to Cyclobutane-1,2-dione by Density Functional Theory Calculations

The reaction pathways for the addition of OH- ion to cyclobutane-1,2-dione I are calculated by density functional theory procedures [B3LYP/6-31+G(d,p)]. Initially, I undergoes attack of the nucleophile, in this case OH- ion, at one of the two equivalent carbonyl carbon atoms leading to formation of a tetrahedral intermediate followed by rearrangement reactions. Density functional theory method (B3LYP) with basis set (6-31+G (d,p) are used to investigate the addition of OH- (hydrated) to the hydrated species of I. The most likely pathway consists in a ring contraction of the tetrahedral intermediate, formed from addition of OH– to I, leading to 1-cyclopropan-1-carboxylic acid.