Draw the structure of an eight-carbon alkene that would yield the following compound (and no others) after treatment with ozone followed by dimethyl sulfide.
The correct answer and explanation is :
To solve this problem, let’s break down the reaction and deduce the structure of the eight-carbon alkene.
Step 1: Understanding the Reaction
When an alkene is treated with ozone ((O_3)) followed by dimethyl sulfide ((DMS), ( (CH_3O)_2S )), it undergoes ozonolysis, which cleaves the carbon-carbon double bond and forms two carbonyl compounds, which could be either aldehydes or ketones depending on the alkene’s structure.
The ozonolysis mechanism is as follows:
- The alkene reacts with ozone, breaking the double bond.
- This results in the formation of an unstable ozonide, which is then reduced by dimethyl sulfide to yield two carbonyl compounds.
Step 2: Identifying the Product Structure
You mentioned that only one product would be formed after ozonolysis. This suggests that the initial alkene must be symmetric, meaning it must have two identical fragments after cleavage.
Step 3: Identifying the Eight-Carbon Alkene
The compound should be an alkene with eight carbon atoms. The simplest symmetric structure for this alkene would be a compound like 4-octene, which has the following structure:
- Structure of 4-octene:
CH₃-CH₂-CH₂-CH=CH-CH₂-CH₂-CH₃
When this is subjected to ozonolysis, the double bond breaks and the resulting fragments would be two identical 4-carbon aldehydes (butanal):
Butanal (CH₃CH₂CHO) is the product of the ozonolysis of 4-octene.
Step 4: The Ozonolysis Result
When 4-octene undergoes ozonolysis, the double bond between the 4th and 5th carbon atoms breaks, forming two butanal molecules:
Reaction:
CH₃-CH₂-CH₂-CH=CH-CH₂-CH₂-CH₃ + O₃ → 2 CH₃CH₂CHO (butanal)
Step 5: Conclusion
Thus, the structure of the eight-carbon alkene is 4-octene, and the product after ozonolysis with dimethyl sulfide would be butanal.
Here is the structure of 4-octene and its ozonolysis product:
- 4-Octene: CH₃-CH₂-CH₂-CH=CH-CH₂-CH₂-CH₃
- Butanal (Product): CH₃CH₂CHO
Here is the image showing the structure of 4-octene and its product after ozonolysis, which results in two molecules of butanal.