Comments on: Birch Reduction https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/ Thu, 09 Mar 2023 21:31:01 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: AH https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-649819 Thu, 09 Mar 2023 19:34:00 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-649819 I’ll email him to see what he says!

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-649818 Thu, 09 Mar 2023 19:28:58 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-649818 In reply to AH.

Hmmm. Once the protonation happens and the pi-system only involves 5 p-orbitals, it’s now become pentadienyl.

]]> By: AH https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-649815 Thu, 09 Mar 2023 18:57:50 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-649815 He called all of them cyclohexadienyl!

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-649813 Thu, 09 Mar 2023 18:53:11 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-649813 In reply to AH.

Depends on what stage of the reduction you’re talking about! The first addition of an electron products a cyclohexadienyl radical anion. After the first protonation happens, you get a pentadienyl radical, which is reduced to a pentadienyl anion by the second electron.

]]> By: AH https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-649794 Thu, 09 Mar 2023 15:13:52 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-649794 My lecturer still called it a cyclohexadienyl radical/anion instead of pentadienyl. Is this something that varies depending on the person?

]]> By: Sunil Suresh Yadav https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-639380 Mon, 03 Oct 2022 05:38:36 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-639380 What is relative tendency of reduction of
1 tripple bond
2 conjugated double bond
3 Aromatic ring

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-634691 Sat, 06 Aug 2022 02:33:27 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-634691 In reply to Jonathan Holmes.

In the queue. Thanks for asking.

]]> By: Jonathan Holmes https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-598375 Mon, 01 Mar 2021 20:28:24 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-598375 Will the Birch reduction be added to the mechanism flashcards?

]]> By: Samira https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-588579 Mon, 23 Nov 2020 18:06:29 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-588579 Why reduction stop at alkene in birch reduction?

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2019/10/17/birch-reduction/#comment-587388 Tue, 03 Nov 2020 03:40:28 +0000 https://www.masterorganicchemistry.com/?p=13436#comment-587388 In reply to Jagadeesh goli.

Generally isolated alkenes are not affected by Birch conditions. In a Birch reduction the “nucleophile” is a solvated electron, and the electrophile is the lowest-unoccupied molecular orbital (LUMO) of the alkene. In a conjugated system the LUMO is considerably lower in energy than for an isolated alkene due to the larger pi-system.

It’s possible to increase the reducing power of the Birch by adding alkylamines (e.g. methylamine for the reduction of dienes like isoprene) but I have not seen examples for the reduction of isolated alkenes.

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