Scheme 2 shows a proposed mechanism for the cycloaddition reaction using ethanol as the solvent and MMO and KI as catalysts. The reaction begins with the activation of CO2 by MMO to give rise to the formation of intermediate A. In parallel, ethanol acts as a Brønsted acid, leading to the activation of the epoxide via intermediate B. Then, opening the ring at B by nucleophilic attack on the less sterically hindered carbon using IK produces C. The alkylcarbonate D is formed after a reaction between B and C. Finally, the intermediate D is the direct precursor of cyclic carbonate 2a. Scheme 2. Proposed mechanism for the cycloaddition of CO2 to epoxides using MMO and KI as catalysts and ethanol as the solvent.