Enantiomer vs Diastereomer

[Mushrooomboy]

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I may be wrong but enantiomers are compounds with all different chiral centers but diastereomers are compounds with 1 or more different chiral centers right?

 

[t5Nitro]

I may be wrong but enantiomers are compounds with all different chiral centers but diastereomers are compounds with 1 or more different chiral centers right?

Correct.

 

[Mushrooomboy]

But in the example given, only 1 chiral center was altered, and the answer was said to be enantiomer when I picked diastereomer did I miss something?

 

[jaybird12]

Both chiral centers have opposite absolute configurations, not just 1 chiral center.

Enantiomers: each chiral C has the opposite absolute configuration as the corresponding chiral C in the other molecule (ex: S & R)
Diastereomers: a mix of the same and opposite absolute configurations; some chiral Cs have the opposite absolute configuration as the corresponding chiral C, some chiral Cs have the same absolute configuration (S & R; R & R; R & S)
Same molecule: all chiral Cs have the same absolute configuration as the corresponding chiral C in the other molecule (S & S; R & R; R & R)

The two molecules in your question have opposite absolute configurations (Left: R,R. Right: S,S). They are enantiomers.
Also, if you draw the mirror image of the molecule on the left and then flip it, you get the molecule on the right, so they are mirror images. But they are also un-superimposable.

 

[Mushrooomboy]

I see, I thought the OH and methyl groups were the same for both molecules. Thanks!