Question

Can ozonolysis be used to determine the structure of an unknown alkene?

Answer 1

Yes, ozonolysis is often used to determine the structure of an unknown alkene.

We can work backwards from the products and figure out what the alkene must have been.

Assume that an unknown alkene produced acetaldehyde and butanone on ozonolysis.

The original alkene must have contained the structures

CH₃CH= and =C(CH₃)CH₂CH₃

Put the pieces together, and you get

CH₃CH=C(CH₃)CH₂CH₃

This may be easier to see with structural formulas.