Illustrated Glossary of Organic Chemistry

Diastereomer: One molecule in a set of stereoisomers that are not enantiomers.




Cis-1,2-dichlorocyclohexane
    
Trans-1,2-dichlorocyclohexane
The cis and trans stereoisomers of 1,2-dichlorocyclohexane are diastereomers. Verify with models.