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Hello, I have a question I'm preparing an exam and I found an exercice.

It's the reaction of the magnesium éthyl ( CH3-CH2-MgBr) + 2,3 époxycyclopentanone. Solvant Et_2O.

We have a ketone and a epoxy.

 CH3-CH2 it's delta - and MGBr delta +.
 
We obtain an alcoolate ( nucleophilic subtitution I think ) and after a alcool with water.

But wich one I have to chose to form an pur enantiomere ? I want to say subtitution on the epoxyde but why it's more the epoxyde than the carbonyl juste with the cycle tension of the epoxyde ? and there's no difference between the 2 carbons of the epoxyde ?

Sorry I couldn't insert an image I'm New.
Thanks for your help. Have a nice day