The most stable intermediate forms first. Explain this statement by showing a reaction coordinate diagram for the formation of a 3° carbocation over a 2° carbocation in the following alkene addition reaction.

Halohydrin formation is a stereospecific reaction. Identify the products of halohydrin formation of the following diastereomeric alkenes to demonstrate this stereospecificity.

Provide a mechanism for the chlorination of cyclohexane. Be sure to include initiation, propagation, and three possible termination steps.

A radical reaction, as it progressed through its propagation steps, involved the following radical species. Suggest which products might form in all possible termination steps (six products are possible).

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)

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

(d)

Using the bond-dissociation energies in Table 5.6,

(a) predict whether or not a fluorine radical would be selective for forming a single radical from propane.

Using the bond-dissociation energies in Table 5.6,

(b) Will the transition state be reactant-like or product-like? Explain your answer.

Using the bond-dissociation energies in Table 5.6,

(a) predict whether or not an iodine radical would be selective for forming a single radical propane.

When (1R,3S)-1-tert-butyl-1,3-dimethylcyclopentane is halogenated, one stereoisomer is produced in excess.

(a) Predict the identity of the major stereoisomer



When (1R,3S)-1-tert-butyl-1,3-dimethylcyclopentane is halogenated, one stereoisomer is produced in excess.

(b) explain why this reaction did not produce an equal mixture of stereoisomers.

Suppose a 2-halobutane was needed for a synthetic sequence. Starting your synthesis with butane, would it be best to put a chlorine or bromine at that position? Explain.

Predict the major products of the following alkane halogenation reactions. [The number of products shown ignores the formation of racemic mixtures.]

(b)

Predict the major products of the following alkane halogenation reactions. [The number of products shown ignores the formation of racemic mixtures.]

(c)

Predict the major products of the following alkane halogenation reactions. [The number of products shown ignores the formation of racemic mixtures.]

(d)

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

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

Predict the major products of the following alkene halogenation reactions. [D is the symbol for deuterium, an isotope of hydrogen.]

(a)

Predict the major products of the following alkene halogenation reactions. [D is the symbol for deuterium, an isotope of hydrogen.]

(b)

HBr and peroxides are also used to generate 1-bromo-1-alkenes. Suggest a starting reactant that would successfully undergo this reaction.

Identify the allylic carbon(s) in the following molecules.

(a)

Identify the allylic carbon(s) in the following molecules.

(b)

Identify the allylic carbon(s) in the following molecules.

(c)

We show in Chapter 12 that C― Br bonds can break to give a carbocation and a bromide anion. For which of the organohalides (A or B) would you expect this process to be fastest? Explain.

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

In the following molecules, identify the carbon where the radical is most likely to form in the first propagation step.

(c)

In the following molecules, identify the carbon where the radical is most likely to form in the first propagation step.

(d)

In the following allylic radicals, identify the carbon where the new C–Br bond is most likely to form in the second propagation step.

(a)