Ozonolysis

Ozonolysis Scheme 2 examples

Ozonolysis Scheme, H2O2

EugenolOzonolysis

Carbonyl oxide (Criegee zwitterion)

Ozonolysis-2

Ozonolysis-alkyne

Ozonolysis is a chemical reaction where ozone (O₃) is used to break down alkenes, alkynes, or some aromatic compounds by cleaving the carbon-carbon double or triple bonds, leading to the formation of aldehydes, ketones, or carboxylic acids. This reaction is significant in both synthetic and analytical chemistry for the functionalization of carbon-carbon multiple bonds and for the identification of the structure of organic compounds.

Mechanism

The mechanism of ozonolysis can be divided into several steps. Initially, the ozone molecule reacts with the carbon-carbon double bond to form a molozonide, which is an unstable intermediate. This molozonide then rearranges to a more stable ozonide. The ozonide can be further reduced (typically with a reducing agent like zinc in acetic acid or dimethyl sulfide) to yield aldehydes, ketones, or a mixture of both, depending on the substituents attached to the original double bond.

Steps of the Mechanism

1. Formation of the molozonide intermediate.
2. Rearrangement of the molozonide to form the ozonide.
3. Reduction of the ozonide to form the final products (aldehydes, ketones, or carboxylic acids).

Applications

Ozonolysis is widely used in organic synthesis to cleave double or triple bonds, allowing for the introduction of oxygen-containing functional groups. This reaction is particularly useful in the synthesis of complex molecules from simpler precursors. Additionally, ozonolysis is employed in the analysis of unsaturated organic compounds, serving as a method to determine the position of double bonds within molecules.

Safety Considerations

Working with ozone requires caution due to its highly reactive and toxic nature. Proper ventilation and protective equipment are essential to prevent exposure. Ozone can cause respiratory irritation and long-term health issues upon prolonged exposure.

See Also

• Organic synthesis
• Alkene
• Alkyne
• Aromatic compound
• Aldehyde
• Ketone
• Carboxylic acid