Part of a synthesis by E. J. Corey and David Watt (Harvard University) involves the Diels-Alder cycloaddition

Question:

Part of a synthesis by E. J. Corey and David Watt (Harvard University) involves the Diels-Alder cycloaddition of the following pyrone and cyclohexenone. The initial reaction gives the endo product, which loses carbon dioxide in a retro-Diels-Alder to generate a diene with predictable stereochemistry and functionality. IR and UV spectroscopy of the final product show that it contains a diene conjugated with an ester, and an unconjugated ketone. Determine the structures of the intermediate and the final product, with particular attention to their stereochemistry.