The following ethers are ranked according to their ability to form explosive peroxides. Explain this ranking based on your knowledge of the reaction mechanism.

For each set of reactive intermediates, rank them in order of reactivity (1 = most reactive).

(b)

Use the information in Table 4-2 to explain why toluene (PhCH₃) has a very high octane rating of 111. Write an equation to show how toluene reacts with an alkyl free radical to give a relatively stable radical.

A student adds NBS to a solution of 1-methylcyclohexene and irradiates the mixture with a sunlamp until all the NBS has reacted. After a careful distillation, the product mixture contains two major products of formula C₇H₁₁Br.

b. Rank these three intermediates from most stable to least stable.

Explain the dramatic difference in rotational energy barriers of the following three alkenes. (Hint: Consider what the transition states must look like.)

Based on the stability of the radicals produced, predict which bond in each pair would have the higher bond-dissociation energy.

(a)

Based on the stability of the radicals produced, predict which bond in each pair would have the higher bond-dissociation energy.

(b)

Based on the stability of the radicals produced, predict which bond in each pair would have the higher bond-dissociation energy.

(c)

Why is a 2° carbon radical more stable than a 1° carbon radical?