Chapter 10, Problem 60CP

(a)

Interpretation Introduction

Interpretation:

The production of iodocubane from Cuban and tetraiodomethane, the propagation cycle has to be proposed.

Concept introduction:

Generally, the steps involved in radical mechanism are categorized into three. The generations of radical are called initiation. The steps involved in movement of unpaired electron from its position come under propagation. Finally, the radicals annihilate each other with bond formation comes under termination step.

Stability of Radicals: Radicals are highly unstable due to its unpaired valence electron of an atom.

The increasing order of radical stability is given below

Benzylic > allylic > tertiary > secondary > primary > methyl

Generally, the bond strength depends on the formation of radical. If radical is involving in resonance then the respective bond strength is considered to be weak.

(b)

Interpretation Introduction

Interpretation:

Three possible termination steps of Cubane have to be provided.

Concept introduction:

Generally, the steps involved in radical mechanism are categorized into three. The generations of radical are called initiation. The steps involved in movement of unpaired electron from its position come under propagation. Finally, the radicals annihilate each other with bond formation comes under termination step.

Stability of Radicals: Radicals are highly unstable due to its unpaired valence electron of an atom.

The increasing order of radical stability is given below

Benzylic > allylic > tertiary > secondary > primary > methyl

Bond strength is depends on the formation of the radical, if the radical is involving in resonance which weakest bond strength.

(c)

Interpretation Introduction

Interpretation:

The reason for 2b as an effective iodination reagent while 2a is not has to be explained.

Concept introduction:

Generally, the steps involved in radical mechanism are categorized into three. The generations of radical are called initiation. The steps involved in movement of unpaired electron from its position come under propagation. Finally, the radicals annihilate each other with bond formation comes under termination step.

Stability of Radicals: Radicals are highly unstable due to its unpaired valence electron of an atom.

The increasing order of radical stability is given below

Benzylic > allylic > tertiary > secondary > primary > methyl

Bond strength is depends on the formation of the radical, if the radical is involving in resonance which weakest bond strength.