Attack on Epoxide: What Did I Do Wrong?

[Prabs3257]

Homework Statement

Reaction on epoxide

Relevant Equations

Electrophile attack

According to me the option that is marked should be the answer because the oEt- will attack the carbon on the epoxide which forms the stable carbocation but in the answer key the answer is given to be d please tell me what i did wrong

 

[mjc123]

No carbocation formed, this is S_N2.

 

[chemisttree]

When an anion attacks, no carboCATION can be formed, right?

 

[chemisttree]

So this is probably going to scramble your noggin a bit... Number the carbons on the starting epoxide (epichlorohydrin) 1 thru 3 starting at the carbon attached to the chlorine.

Which carbon is most susceptible to attack by the alkoxide? C1? C3? Remember that the highly strained 3-member oxirane makes oxygen a much better leaving group than Cl-.