Chapter 24, Problem 24.23P

Interpretation Introduction

(a)

Interpretation:

The molozonide, the ozonide, and the products that are formed in given reaction are to be drawn.

Concept introduction:

Oxidative cleavage with ozone, ${\text{O}}_{\text{3}}$, is a process called ozonolysis. In Step 1, ozone undergoes a [4+2] cycloaddition to the alkene to produce a molozonide. Step 1 more specifically is called a 1, 3-dipolar cycloaddition because ozone is a 1, 3-dipolar compound, characterized by resonance delocalization of charge over atoms that have a 1, 3-positioning. Step 2 is a [4+2] cycloelimination, which breaks the carbon-carbon single bond. Step 3 is another [4+2] cycloaddition, also a 1, 3-dipolar cycloaddition, producing an ozonide. Ozonides are unstable and can be explosive, so they are generally not isolated. ${\text{H}}_{\text{2}}{\text{O}}_{\text{2}}$ oxidizes the initial ${\text{H}}_{\text{2}}\text{C=O}$ to ${\text{CO}}_2$.

Interpretation Introduction

(b)

Interpretation:

The molozonide, the ozonide, and the products that are formed in the given reaction are to be drawn.

Concept introduction:

Oxidative cleavage with ozone, ${\text{O}}_{\text{3}}$, is a process called ozonolysis. In Step 1, ozone undergoes a [4+2] cycloaddition to the alkene to produce a molozonide. Step 1 more specifically is called a 1, 3-dipolar cycloaddition because ozone is a 1, 3-dipolar compound, characterized by resonance delocalization of charge over atoms that have a 1, 3-positioning. Step 2 is a [4+2] cycloelimination, which breaks the carbon-carbon single bond. Step 3 is another [4+2] cycloaddition, also a 1, 3-dipolar cycloaddition, producing an ozonide. A reducing agent prevents the aldehyde in the product from being oxidized.