Later, Ruiz-Lopez et al. studied Diels-Alder reactions of cyclopentadiene and methyl acrylate (Figure ) using ab initio calculations . They found that because the solvent's electric field changes the shape of the potential energy surface, a direct change in the overall reaction mechanism is seen with solvation. It is argued that only adding the solvation energy to the gas-phase energy is not sufficient to determine the reaction path in solution. However, they also maintain that continuum theory models are sufficient for capturing some specific interactions with solvents, such as hydrogen-bonding, since overall electrostatic effects will implicitly include these properties. Another simulation study on the reaction of methyl acrylate with cyclopentadiene was done by Sheehan and Sharratt using molecular dynamics . The reaction was studied in both methanol and n-hexane. The result showed that the endo/exo selectivity of the reaction products is related to the difference in the solvated transition states' free energies. Further, the rates and selectivity were affected by properties of the solvent, such as their polarity and H-bonding ability. In methanol, the product was energetically favored as compared to in n-hexane; this effect was explained by the similarity in polarity between the product and methanol.