11. Radical Reactions

Can you make a 1° bromoalkane like (3-bromopropyl)cyclopentane using alkane halogenation? Why or why not?

Predict the major product of the following bromination reactions.

(b)

Predict the major product of the following bromination reactions.

(c)

For the following reaction, answer questions (a)–(d).

(b) Which is the weakest bond in molecule A?

For the following reaction, answer questions (a)–(d).

(d) Given your choice in (b), why is it the weakest bond?

A halogenation intended to make compound A formed B instead.

(a) Suggest a mechanism for the intended formation of A.

A halogenation intended to make compound A formed B instead.

(c) Given the two mechanisms you drew, why might B have formed selectively?

In the following reaction, which C―H bond would be most likely to react with a bromine radical?

Tributyltin hydride (Bu₃SnH) is often used as a 'radical carrier' in radical reactions. Which bond would you expect to be weaker, Sn–H or C–H? How might this relate to radical stability? Explain your answer.

Haloalkanes can be reduced to alkanes using radical reactions involving Bu₃SnH and a catalytic amount of AIBN. Suggest a mechanism for this reaction. [Pay close attention to the bonds formed and broken in developing your mechanism.]

What are the product(s) of each of the following reactions? Disregard stereoisomers.

e.

What are the product(s) of each of the following reactions? Disregard stereoisomers.

d.

How many alkyl halides are obtained from monochlorination of the alkanes in Problem 4 if stereoisomers are included?

h.

How many alkyl halides are obtained from monochlorination of the alkanes in Problem 4 if stereoisomers are included?

g.

How many alkyl halides are obtained from monochlorination of the alkanes in Problem 4 if stereoisomers are included?

f.