Question

Question: One step in the synthesis of dodecahedrane (Section 4.11) involved reaction of the tetraene C with dimethylacetylene dicarboxylate (D) to afford two compounds having molecular formula C₁₆H₁₆O₄ . This reaction has been called a domino Diels–Alder reaction. Identify the two products formed.

Short answer

Answer

Step-by-step solution

Diels-Alder reaction

The Diels-Alder product is a cycloaddition reaction in which diene reacts with a dienophile.

Dienophile

Dienophile generally contains electron-withdrawing groups. Therefore, diene reacts fast by donating its electron to dienophile.

Explanation

Compound C is a diene and compound D is a dienophile. The dienophile has two ester groups. One of the dienes in the ring first reacts with the alkyne (dienophile) and forms the first Diels-Alder product.

The first product again undergoes intramolecular cycloaddition and forms the second Diels-Alder product.

The reaction scheme is shown below:

Reaction of diene and dienophile