Final answer:
The incorrect statement about the Diels-Alder reaction is that it's a substitution reaction (Option A)
Step-by-step explanation:
The Diels-Alder reaction is actually a cycloaddition reaction involving a cyclic diene and a dienophile to form a six-membered ring. This reaction is characterized by the concerted movement of electrons to form new σ-bonds and a π-bond simultaneously, creating a six-membered ring structure, as seen in the reaction between butadiene and ethene.
The Diels-Alder reaction is a type of cycloaddition reaction that involves the reaction between a cyclic diene and a dienophile. It forms a six-membered ring as a product. It is not a substitution reaction, which involves the replacement of one atom or group of atoms in a molecule.
The option that is not true about the Diels-Alder reaction is A) It's a type of substitution reaction.