Question

Question: Draw the products formed when each compound is treated with one equivalent of HBr.

a.

b.

c.

Short answer

a.

b.

c.

Step-by-step solution

Addition of HBr

The addition of HBr takes place via the “carbocation formation.”

1,2 and 1,4 addition

During the addition of HBr, two carbocationic intermediates form as part of the reaction.

Products of given reactions

a. The double bonds are not conjugated. Hence, the addition of HBr leads to the formation of only one addition product.

Product of a

b.The given diene is conjugated. Hence, the addition of the strong acid HBr leads to the formation of two products, i.e., 1,2 and 1,4 addition products.

The addition products of the reaction are:

Products of bc. The given diene is conjugated. Hence, the addition of the strong acid HBr leads to the formation of two products, i.e., 1,2 and 1,4 addition products.

The addition products of the reaction are:

Products of c