1. The problem statement, all variables and given/known data https://www.box.com/s/qs19ng6qvcget7g69ad3 [Broken] 2. Relevant equations 3. The attempt at a solution I think that there are two possibilities. First, C2H5O- can attack at the epoxide ring by the SN2 mechanism (i guess the attack will take place at the less substituted carbon in the epoxide ring) and the second is that nucleophilic substitution can place at the carbon attached to oxygen by the SN2 mechanism. But which of the two possibilities would happen and why? I am stuck here. The answer given is D but why does the epoxide ring does not react? Any help is appreciated.