Understanding Ozonolysis and Product Formation

Ozonolysis is a reaction where an alkene is cleaved by ozone (O₃) to form carbonyl compounds (aldehydes or ketones). The key point is that each carbon in the double bond becomes a carbonyl carbon. For an alkene to give two different products upon ozonolysis, it must be unsymmetrical—meaning the two sides of the double bond are not identical.

Step-by-Step Analysis of Each Option:

Step 1: Analyze the structure of each alkene. Determine if it is symmetrical or unsymmetrical.

Step 2: For unsymmetrical alkenes, ozonolysis will yield two different carbonyl compounds. For symmetrical alkenes, identical products are formed.

Option 1: Cyclohexene. This is a symmetrical alkene. Ozonolysis gives a single dicarbonyl compound: OHC-(CH₂)₄-CHO. Only one product.

Option 2: 2,3-Dimethylbut-2-ene. This is a symmetrical alkene (both sides are (CH₃)₂C=). Ozonolysis gives two identical ketones: 2 molecules of (CH₃)₂C=O.

Option 3: Propene (CH₃-CH=CH₂). This is an unsymmetrical alkene. One side is -CH₃, the other is -CH₂H. Ozonolysis will yield two different products: formaldehyde (HCHO) and acetaldehyde (CH₃CHO).

Option 4: Ethene (H₂C=CH₂). This is a symmetrical alkene. Ozonolysis gives two identical molecules of formaldehyde (HCHO).

Final Answer: The compound that gives two different products on ozonolysis is Propene (Option 3).

Related Topics:

Alkenes: Structure and Reactivity
Oxidative Cleavage Reactions
Carbonyl Compounds (Aldehydes and Ketones)
Stereochemistry in Ozonolysis (if applicable)

Key Formulae and Theory:

The general reaction for ozonolysis of an alkene is:

R - CH = CH - R^{'} \overset{1 . O_{3}, 2 . Zn / H_{2} O}{\to} R - CHO + R^{'} - CHO

If R ≠ R', two different aldehydes/ketones are formed. If the alkene is terminal (one side is H), formaldehyde (HCHO) is a product. If the carbon is disubstituted, a ketone (R₂C=O) is formed.