Predict the products of the following proposed Diels–Alder reactions.
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Verified step by step guidance

1. Step 1: Identify the components of the Diels–Alder reaction. The reaction involves a conjugated diene (cyclohexadiene) and a dienophile (the molecule with two aldehyde groups attached to a triple bond). The diene will provide the π-electrons, while the dienophile will act as the electron-deficient partner.
2. Step 2: Analyze the dienophile. The triple bond in the dienophile is electron-deficient due to the electron-withdrawing aldehyde groups (-CHO). This makes it highly reactive toward the diene in the Diels–Alder reaction.
3. Step 3: Predict the regiochemistry. The electron-withdrawing groups on the dienophile will direct the reaction such that the new bonds form in a way that maximizes stability. The aldehyde groups will likely end up on the same side of the newly formed six-membered ring.
4. Step 4: Draw the product structure. The Diels–Alder reaction will result in a six-membered ring where the triple bond of the dienophile becomes a double bond, and the conjugated diene forms two new single bonds with the dienophile. The aldehyde groups will remain attached to the carbons where they were originally located.
5. Step 5: Confirm stereochemistry. The reaction is stereospecific, meaning the substituents on the dienophile (aldehyde groups) will retain their relative orientation (cis or trans) in the product. Since both aldehyde groups are on the same side of the dienophile, they will remain cis in the final product.

Key Concepts

Diels–Alder Reaction

The Diels–Alder reaction is a [4+2] cycloaddition reaction between a conjugated diene and a dienophile, resulting in the formation of a six-membered ring. This reaction is a key method in organic synthesis for constructing cyclic compounds and is characterized by its stereospecificity and regioselectivity, making it a powerful tool for chemists.

Conjugated Dienes

Conjugated dienes are compounds that contain two double bonds separated by a single bond, allowing for resonance stabilization. This structure enhances their reactivity in Diels–Alder reactions, as the diene can adopt an s-cis conformation, which is necessary for effective overlap with the dienophile's π orbitals during the reaction.

Dienophile

A dienophile is an electron-deficient alkene or alkyne that reacts with a diene in a Diels–Alder reaction. The presence of electron-withdrawing groups, such as carbonyls or nitriles, on the dienophile increases its reactivity by stabilizing the transition state, thus facilitating the cycloaddition process and influencing the regioselectivity of the product.