[G O D I V A]

I just can't get my head around these 2.  What's the difference between enantiomers and diastereoisomers

[Dan]

They are two different types of stereoisomer.

Two compounds are related as enantiomers if they are non-superimposable (ie different) but have the same atom connectivity and molecular formula (stereoisomers)  and also happen to be mirror images of each other. Enantiomers have the same relative configuration (but different absolute configuration), eg. D-glucose and L-glucose.

Two compounds are related as diastereoisomers if they are non-superimposable (ie different) but have the same atom connectivity and molecular formula (stereoisomers)  but are not mirror images of each other. Diastereoisomers have different relative stereochemistry, eg. D-glucose and D-galactose.