datQvault Ochem Test 2 Q 30

[Moka11]

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Just out of curiosity, the explanation says that the KOC(CH3)3 would actually do E2.
Wouldn't the O- actually quickly pickup a free floating H+ being that its sitting in H-Br?

 

[roquer2]

Just out of curiosity, the explanation says that the KOC(CH3)3 would actually do E2.
Wouldn't the O- actually quickly pickup a free floating H+ being that its sitting in H-Br?

Review the differences between SN2 and E2.

So looking at the reaction, we have a GREAT leaving group. Now refer to the base. Deprotonate your nucleophile and wouldn't you know, that negative charge is on the oxygen PLUS (and take note of this, bc this is a COMMON THEME of E2) that nucleophile is a huge, bulky base. In terms of simple ochem, assume elimination via strong, bulky bases with GREAT nucleophilicity. Hope this helped

 

[Moka11]

Review the differences between SN2 and E2.

So looking at the reaction, we have a GREAT leaving group. Now refer to the base. Deprotonate your nucleophile and wouldn't you know, that negative charge is on the oxygen PLUS (and take note of this, bc this is a COMMON THEME of E2) that nucleophile is a huge, bulky base. In terms of simple ochem, assume elimination via strong, bulky bases with GREAT nucleophilicity. Hope this helped

Ya but any base would be more than happy to take an H+. In fact in E1/E2 you lose an H+. Hence if one is floating around from the H-Br I find it funny that the base would go through all that hard work of E2 if theres plenty of free H+'s already floating around.

Not really so important. Im just trying to understand DQV's answer.

 

[roquer2]

Ok, I see exactly where you are getting confused 👍

Interpret it as, instead of using the ethanol (or whatever the alkyl alcohol given in the question is), you actually use a strong, bulky base. Would you increase the rate of SN2, or would it take the other route, E2?

Hope that cleared it up!

 

[Moka11]

Ok, I see exactly where you are getting confused 👍

Interpret it as, instead of using the ethanol (or whatever the alkyl alcohol given in the question is), you actually use a strong, bulky base. Would you increase the rate of SN2, or would it take the other route, E2?

Hope that cleared it up!

It did. Thanks!
👍