2-Ethyl-1-hexanol is needed for the synthesis of the sunscreen octyl p-methylcinnamate. It can be synthesized by malonic ester synthesis, with the following mechanism: 1. Deprotonation of diethyl malonate to yield enolate 1; 2. SN2 reaction of enolate 1 with butyl bromide to yield addition 2; 3. Deprotonation of addition 2 to yield enolate 3; 4. SN2 reaction of enolate 3 with ethyl bromide to yield addition 4; 5. Treatment of addition 4 with base, and then with acid and heat, to yield acid 5; 6. Reduction of acid 5 with LiAlH4 yields the final product. Write out the mechanism on a separate sheet of paper, and then draw the structure of addition 4. You do not have to consider stereochemistry. Draw enolate anions in their carbanion form. Do not include counter-ions, e. g., Na , I-, in your answer. Do not draw organic or inorganic by-products.