Provide an example of the diene and dienophile in the Diels-Alder reaction.

An example of the diene and dienophile in the Diels-Alder reaction is 1,3-butadiene and ethene.

The Diels-Alder reaction is a type of cycloaddition reaction that involves the reaction between a diene and a dienophile to form a cyclic compound. The diene is a molecule that contains two double bonds, while the dienophile is a molecule that contains a double bond and an electron-withdrawing group.

1,3-butadiene is an example of a diene that can undergo the Diels-Alder reaction. It contains two double bonds separated by a single bond, and can react with a dienophile to form a six-membered ring. Ethene is an example of a dienophile that can react with 1,3-butadiene to form cyclohexene.

During the reaction, the diene and dienophile undergo a concerted mechanism, where the two double bonds of the diene add to the double bond of the dienophile to form a cyclic compound. The reaction is highly stereospecific, meaning that the stereochemistry of the reactants determines the stereochemistry of the product.

The Diels-Alder reaction is an important tool in organic synthesis, as it allows for the formation of cyclic compounds with high stereochemical control. It is commonly used in the synthesis of natural products, pharmaceuticals, and materials science.