Which of the following statements about the diels-alder reaction are true?
a. it is a reaction involving pi-electrons.
b. it is a [1+3] cycloaddition.
c. it is a stepwise reaction.
d. it is *not* a reaction favored by entropy considerations.
e. it is a photochemical reaction.

A.It is a reaction involving pi-electrons.

D.It is *not* a reaction favored by entropy considerations.

Explanation:

The Diels-Alder reaction is a [4+2]- cycloadition that involoves pi-electrons (4 from the diene and 2 from the dienophile).

The reaction is favored by the formation of new sigma bond, since they are more stable than pi-bonds. This reaction is not favored by entropy because there are 2 reactants and one product and the order increases.

The reaction happens in one step.

i'm assuming that it's c.) red bank..