Comments on: Epoxides – The Outlier Of The Ether Family https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/ Mon, 07 Nov 2022 08:39:50 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: James Ashenhurst https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-599874 Fri, 16 Apr 2021 20:25:20 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-599874 In reply to Mary.

Epoxides do have ring strain, but they can still form. The nucleophile (alkoxide) is in close proximity to the electrophile so ring formation is quite fast.

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By: Mary https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-599752 Mon, 12 Apr 2021 15:33:27 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-599752 Why epoxidation is happened in halohydrin cyclization while the angle pressure will arise?

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By: James Ashenhurst https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-552555 Sat, 13 Apr 2019 09:00:02 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-552555 In reply to AJ.

I did – it’s here. https://www.masterorganicchemistry.com/2013/04/02/alkene-addition-pattern-3-the-concerted-pathway/ Epoxidation of aliphatic alkenes is “syn” addition ; both new C-O bonds are formed on the same face of the alkene. This is true regardless of whether you have a cis or trans alkene.

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By: James Ashenhurst https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-552554 Sat, 13 Apr 2019 08:56:26 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-552554 In reply to James B.

Fixed, finally. Thanks!

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By: James B https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-544378 Wed, 28 Nov 2018 04:50:30 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-544378 In reply to James.

Hi my genius namesake! Just a small note, you didn’t fix that typo (“epoxide” instead of “alkene”) in the Epoxide Synthesis (1) diagram.

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By: AJ https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-530874 Fri, 13 Apr 2018 04:07:56 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-530874 Can you please make a page explaining stereochemistry of epoxidation of aliphatic alkenes. I am confused is there syn addition or anti addition in epoxidation. What happens in the cis and trans configuration?

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By: James https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-441488 Tue, 22 Dec 2015 01:28:25 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-441488 In reply to Max.

For acid-base reactions to be *irreversible* there needs to be a pKa difference of 10.

For ROH and NaOH you’ll have an equilibrium where the two species are about equal in concentration. However once you form RO- it’s a fast reaction to form the epoxide, and that spits out Br- . Eventually you’ll end up with the final product.

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By: Max https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-440906 Mon, 14 Dec 2015 16:26:46 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-440906 Didn’t you say that for acid-base reactions to occur, we need a pKa difference of about 10?
In the first example, the base is OH- and the acid is ROH… So what’s going on?

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By: James https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-358527 Fri, 30 Jan 2015 03:00:36 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-358527 In reply to Loïc.

Ah yes. Thanks for the spot. Fixed!

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By: Loïc https://www.masterorganicchemistry.com/2015/01/26/epoxides-the-outlier-of-the-ether-family/#comment-357793 Tue, 27 Jan 2015 23:39:10 +0000 https://www.masterorganicchemistry.com/?p=8703#comment-357793 I think you made a mistake when talking about the preparation of epoxides.

You say:

“Treating an epoxide with a “peroxyacid” (that’s a carboxylic acid containing an extra oxygen) leads to direct formation of an epoxide.”

when it should be:

“Treating an alkene with a “peroxyacid” (that’s a carboxylic acid containing an extra oxygen) leads to direct formation of an epoxide.”

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