2,6-octadione is produced by ozonolysis of an alkene. What is the structure of that alkene? Show your reasoning, including a chemical reaction with the correct reagents and reaction conditions.

Answer 1

Hi Brittany,

in order to approach this problem, it's helpful to label the carbons of the 2,6-octadione. Once you do this, you know that C2 and C6 used to be connected before the ozonolysis took place so if you draw connect those two carbons with a double bond and remove the carbonyl groups, you will arrive at 1-ethyl-2-methylcyclopentene (a cyclopentene with a methyl and ethyl group coming off the double bond).

For the reaction, step 1 will be O₃ (the ozonolysis step) and step 2 can be a reductive or oxidative workup since your product is two ketones so DMS (SMe₂) would be fine as a reductive workup for example.

In conclusion:

1-ethyl-2-methylcyclopentene -----> 1) O₃, 2) DMS -----> 2,6-octadione

Let me know if anything still doesn't make sense!