Destroyer Orgo #133

[DATkiller]

Advertisement - Members don't see this ad

Hey guys. Can anyone explain the sterochemistry of the second step? Why is that an anti reaction and not a syn reaction?

 

[meant2be10]

Peroxyacid followed by H30+ always results in an anti-glycol

 

[amh137]

It's an anti addition because when you add a peroxy acid, you form the cyclic oxonium ion which can form either above or below the plane. Therefore, when you add the acid, it can only add opposite (above/below) depending on where the oxonium ion forms.