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 :
The eight-carbon alkene that, upon ozonolysis followed by treatment with dimethyl sulfide, yields only one product is 1-octene.
Structure of 1-Octene:
CH₂=CH(CH₂)₆CH₃
Explanation:
Ozonolysis is a reaction where ozone (O₃) cleaves the carbon-carbon double bond (C=C) of alkenes, resulting in the formation of carbonyl compounds such as aldehydes and ketones. When 1-octene undergoes ozonolysis, the reaction proceeds as follows:
- Ozonolysis Reaction:
- The ozone molecule adds to the double bond of 1-octene, forming a molozonide intermediate.
- This intermediate rearranges to form an ozonide, which is a cyclic compound containing three oxygen atoms.
- Reductive Work-up with Dimethyl Sulfide:
- The ozonide is treated with dimethyl sulfide ((CH₃O)₂S), which reduces the ozonide, cleaving the C=C bond.
- This cleavage results in two molecules of propan-2-al (acetone), a ketone.
The overall reaction can be summarized as:
CH₂=CH(CH₂)₆CH₃ + O₃ → 2 CH₃COCH₃
Therefore, the ozonolysis of 1-octene followed by treatment with dimethyl sulfide exclusively produces acetone as the sole product.
This outcome is specific to 1-octene due to its terminal position of the double bond. Other alkenes with internal double bonds or different substituents would yield a mixture of products upon ozonolysis, making 1-octene the unique precursor that yields only acetone under these conditions.