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.

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 answer this question, we need to understand ozonolysis of alkenes and how to work backward from the ozonolysis products to identify the original alkene.

Step-by-step reasoning:

1. Understanding Ozonolysis

Ozonolysis is an organic reaction where an alkene is cleaved by ozone (O₃), resulting in two carbonyl compounds, typically aldehydes or ketones. When the reaction is followed by a reductive workup (e.g., with dimethyl sulfide, DMS), each double bond is split and replaced with a C=O group.

2. What Information Is Given?

You’re told that ozonolysis followed by dimethyl sulfide yields a single product — that is, only one kind of carbonyl compound. This suggests symmetry in the molecule, because cleaving a double bond yields identical fragments.

So, we are to draw an eight-carbon alkene that, upon ozonolysis and reduction with DMS, produces a single carbonyl compound.

3. Work Backward from the Product

Let’s assume the ozonolysis yields only 2 molecules of butanal (CH₃CH₂CH₂CHO). That means the original alkene must be symmetric and must split into two butanal molecules.

4. Combine the Two Butanal Units

Butanal has 4 carbons. If two butanal molecules are formed from a single alkene, the original compound must be oct-4-ene (CH₃CH₂CH=CHCH₂CH₂CH₃), a symmetric alkene with the double bond at the center.

✅ Correct Answer:

The original alkene is oct-4-ene, which has the structure:

CH₃–CH₂–CH₂–CH=CH–CH₂–CH₂–CH₃

Why This Works:

This satisfies the requirement that only one compound is formed after ozonolysis and dimethyl sulfide treatment.