11. Radical Reactions

b. Calculate ΔH° for each step in this reaction.

c. Calculate the overall value of ΔH° for this reaction.

What alkyl halide will be obtained in greatest yield? Ignore stereoisomers.

b.

Explain why iodine (I₂) does not react with ethane, even though I₂ is more easily cleaved homolytically than the other halogens.

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.]

When a student attempted a bromination to produce compound A, they generated compound B instead. Rationalize the formation of B using the arrow-pushing formalism.

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.

What alkane, with molecular formula C₅H₁₂, forms only one monochlorinated product when it is heated with Cl₂?

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

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

Alkoxy radicals (R—O•) are generally more stable than alkyl (R•) radicals. Write an equation showing an alkyl free radical (from burning gasoline) abstracting a ­hydrogen atom from tert-butyl alcohol, (CH₃)₃COH. Explain why tert-butyl alcohol works as an antiknock additive for gasoline

The following transformation was found to occur in areas with large NO₂ emissions. Suggest a mechanism for the reaction (J. Phys. Chem. 2013, 117, 14132–14140). [Hint: Use the fishhook arrows associated with radical reactions.]

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

e.

For each alkane,

3. which monobrominated derivatives could you form in good yield by free-radical bromination?

c. 2-methylpentane

d. 2,2,3,3-tetramethylbutane

How many monochlorination products would be obtained if all stereoisomers are included?