Assume general laboratory reagents and butadiene are available.
Which of the following sequences could accomplish the following synthesis?
Observe the stereochemical data on either side of the equation – both Cl and COOH groups remain trans;
This points to a nifty implementation of the Diels-Alder reaction:
The product from above on catalytic hydrogenation completes the synthesis.
Watch the video for more on the Diels-Alder reaction – a reaction that won
the scientist duo Otto Diels and Kurt Alder a Nobel prize in Chemistry in 1950.