OC question from Bootcamp

[hope_to_match]

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How come there is no inversion of configuration? Isn't this an Sn2 reaction? Thanks...

 

[Minion]

Inversion only applies if it has a Chiral center.

 

[Koalafied]

How come there is no inversion of configuration? Isn't this an Sn2 reaction? Thanks...

http://s1281.photobucket.com/user/E...nShot2013-09-10at40343PM_zps02d3653b.png.html

https://www.khanacademy.org/science...opening-reactions-of-epoxides--acid-catalyzed

 

[hope_to_match]

https://www.khanacademy.org/science...opening-reactions-of-epoxides--acid-catalyzed

this doesnt answer my question. i know how to open the epoxide rings. i was confused about why there is no inversion.


Minion, hmm..isnt that a chiral center there?

 

[helloworld9]

Technically there is inversion around that carbon. If you check the rotation, the original compound is R and the correct answer in green is S which means that there is inversion (which is true for acid catalyzed epoxide ring opening). However if you see your answer and assign chirality you'll find that it is R like the original compound and thus did not invert. So the answer in green would be correct...super sneaky problem!

You might wanna double check with Ari about this though 😛

 

[Masterus]

It is inverted. If you look at it closely, your leaving group is the oxygen of the epoxide and your nucleophile is your ethanol, which has attacked from the other side. The groups have switched sides so the chirality changes as well.

 

[hope_to_match]

thanks guys i see it now!

 

[Ari Rezaei]

Technically there is inversion around that carbon. If you check the rotation, the original compound is R and the correct answer in green is S which means that there is inversion (which is true for acid catalyzed epoxide ring opening). However if you see your answer and assign chirality you'll find that it is R like the original compound and thus did not invert. So the answer in green would be correct...super sneaky problem!

You might wanna double check with Ari about this though 😛

👍 Always check the configurations, never assume how it's "supposed" to look.

 

[hope_to_match]

👍 Always check the configurations, never assume how it's "supposed" to look.

yeah..that was my mistake! good quesiton though. i find it very simply and yet tricky!