Ozonolysis of which of the following alkenes give propan-2-one and Methanal ?

Question

Accepted Answer

Ozonolysis is a reaction where an alkene is cleaved by ozone to form carbonyl compounds. In this case, we are looking for an alkene that, upon ozonolysis, yields propan-2-one (acetone) and methanal (formaldehyde).

1. **Option 1: 2-Methyl propene**
   - 2-Methyl propene has the structure CH₃-C(CH₃)=CH₂. When ozonolysis is performed on this alkene, the double bond is cleaved, and each carbon atom involved in the double bond is converted into a carbonyl group. The resulting products are propan-2-one (CH₃-CO-CH₃) and methanal (H-CHO). This matches the desired products, confirming that 2-Methyl propene is the correct answer.

2. **Option 2: But-2-ene**
   - But-2-ene has the structure CH₃-CH=CH-CH₃. Ozonolysis of this alkene would result in two molecules of ethanal (CH₃-CHO), not propan-2-one and methanal. Therefore, this option is incorrect.

3. **Option 3: Propene**
   - Propene has the structure CH₃-CH=CH₂. Ozonolysis of propene yields ethanal (CH₃-CHO) and methanal (H-CHO). While methanal is one of the desired products, ethanal is not, making this option incorrect.

4. **Option 4: But-1-ene**
   - But-1-ene has the structure CH₂=CH-CH₂-CH₃. Ozonolysis of this alkene would produce methanal (H-CHO) and propanal (CH₃-CH₂-CHO). Although methanal is one of the desired products, propanal is not, so this option is incorrect.

In conclusion, only 2-Methyl propene (Option 1) yields the desired products of propan-2-one and methanal upon ozonolysis, making it the correct choice.