3. (6 points) The synthesis of cosalane, a new anti-HIV agent, has the following step: COOH COOH COOH HO ÇOOH сон H2SO4 HO HO OH CI 2 equiv 1 equiv Final Product Intermediate X (a) Draw an arrow-pushing mechanism for the formation of intermediate X. Show clearly how chemists rationalize the regioselectivity actually observed in the reaction. Resonance structures may help your argument. (b) Intermediate X is rapidly transformed under the reaction conditions to the final product. What is the structure of the Electrophilic reactive intermediate responsible for this rapid conversion?