Organic Chemistry: Concepts and Applications - Headley Allan D. 2020
Free Radical Substitution Reactions Involving Alkanes
End of Chapter Problems
1. 14.11 Classify each of the following radicals as primary, secondary, or tertiary.
2. 14.12 Give the major organic product for the monobromination of each of the following compounds?
3. 14.13 For the chlorination of cyclopentane, cyclopentylcyclopentane was isolated as one of the products. Explain by an appropriate mechanism how this product was formed.
4. 14.14 Give the structure of the reactant or major organic product needed to complete the following reactions.
5. 14.15 For each of the following compounds, predict the major product of free radical bromination. Remember that bromination is highly selective.
1. Cyclohexane
2. 2,2,3-Trimethylbutane
3. 2,3-Dimethylbutane
4. 1,2-Dimethylcyclohexane
6. 14.16 Starting with 2-methylbutane, show how you would synthesize 2-methyl-2-butene. Indicate clearly all reagents and reaction conditions used in the reaction.
7. 14.17 Two hydrocarbons, A and B, each has the formula C5H10. In a reaction with Cl2, A gave one monochlorinated product, C5H9Cl. B, however, gave four different monochlorinated products, each being C5H9Cl. What are the structures of A and B?
8. 14.18 A hydrocarbon with the formula C5H12 reacts with Cl2 in the presence of light gave a mixture of four structural isomers, each with the formula C5H11Cl. What is the structure of the starting hydrocarbon, C5H12?
9. 14.19 Give the structure of a cyclic unsaturated hydrocarbon of C5H10 which when it reacts with chlorine in the presence of light gives three different mono-chlorinated products. Give the structure of each of the product produced.
10. 14.20 2-Methylbutane has different types of hydrogens, i.e. primary, secondary, and tertiary. Give complete structures for each of the different mono chlorination substitution products that would result from the reaction of 2-methylbutane with chlorine in the presence of light.
11. 14.21 Give complete structures and IUPAC names for each of the different mono chlorination substitution products that would result from the reaction of methylcyclopentane with chlorine in the presence of light.
12. 14.22 For the molecule shown below, there is a homolytic cleavage of the O─Cl bond in the presence of heat to produce two radicals, which eventually yield the products shown. Give a mechanistic explanation for the formation of the products shown.
13. 14.23 For the reaction shown below, two isomers were obtained: the expected free radical substitution product and an unexpected free radical substitution product. Using appropriate arrows to indicate electron movement, give a step-by-step description of a mechanism to explain the products shown for this free radical substitution reaction, i.e. initiation, propagation, and termination steps.
14. 14.24 In an attempt to synthesize compound C (shown in the reaction below), the following sequence of reactions was carried out. The actual product isolated, however, was not the desired product, C, but an unexpected isomer, which is shown in the box. Give structures for the lettered compound in the sequence of reactions and give a mechanistic explanation for the formation of this unexpected isomer that was formed in the final step of the reaction sequence.