Why Is the Diels-Alder Reaction Called a Thermal [4+2] Cycloaddition

question 52

Multiple Choice

Why is the Diels-Alder reaction called a thermal [4+2] cycloaddition?

• A)Because the reaction is initiated by heat; the diene has four p electrons and the dienophile has two p electrons.
• B)Because the reaction is initiated by light; the diene has four p electrons and the dienophile has two p electrons.
• C)Because the reaction is initiated by heat; the dienophile has four p electrons and the diene has two p electrons.
• D)Because the reaction is initiated by light; the dienophile has four p electrons and the diene has two p electrons.