This reaction involves a conjugate addition reaction followed by an intramolecular Claisen condensation. The steps involved are as follows: 1. Conjugate addition of methyl carbanion (from the Gilman reagent) to form enolate ion 1; 2. Cyclization to form tetrahedral intermediate 2; 3. Collapse of the tetrahedral intermediate and expulsion of methoxide ion completes the reaction to form the final product. Write out the reaction on a separate sheet of paper, and then draw the structure of tetrahedral intermediate 2.