Comments on: The Ruff Degradation and Kiliani-Fischer Synthesis https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/ Mon, 19 Sep 2022 15:43:45 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: James Ashenhurst https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-633566 Wed, 20 Jul 2022 20:19:43 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-633566 In reply to Mattia Pascal.

Shoot. You are correct. Thank you for pointing that out, I’ll fix it.

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-620050 Tue, 08 Feb 2022 20:53:39 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-620050 In reply to Aurelius.

Good catch. I believe you are correct. Will fix this.

]]> By: Aurelius https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-619946 Mon, 07 Feb 2022 10:29:53 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-619946 Are you certain that you get a Fe(IV) species? I would argue that Fe3+ reacts with H2O2 to form H+ and the *O-OH radical. The formed Fe2+ then reduces another equivalent of H2O2 to -OH (which reacts with the previously formed H+ to make water) and HO* radical. HO-O* abstracts a proton from -COOH to give -COO*, then loss of CO2 and a new carbon-centered radical. This can then react with HO* to form the hydrate. In this last step, several other pathways are also likely, though they all lead to the same result.

]]> By: Sourish Dutta https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-607935 Sat, 23 Oct 2021 16:30:41 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-607935 I have a Question that when glucose is oxidised with strong oxidising agents (like with conc HNO3)why do the 2 degree alcohols in between not get oxidised??

]]> By: Mattia Pascal https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-603014 Wed, 30 Jun 2021 15:37:23 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-603014 I think there’s a mistake at the end of the Kiliani-Fischer synthesis paragraph. D threose should be 2S-3R , not 2R-3S

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-566218 Fri, 04 Oct 2019 16:52:16 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-566218 In reply to Anirudh Saripalli.

The H2O2 oxidizes the iron to a very unstable Fe(IV) species, which in turn rips an electron off of an oxygen from the carboxylate. Loss of CO2 then occurs, resulting in a carbon based radical, which in turn is oxidized once more by Fe to give a new carbocation. The resonance form of that carbocation is a protonated aldehyde, which then is deprotonated to give the neutral aldehyde.

]]> By: Anirudh Saripalli https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-566217 Fri, 04 Oct 2019 16:46:28 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-566217 Can you pls explain what does FeSO4 + H2O2 do. Is it an oxidising agent?

]]> By: James Ashenhurst https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-558293 Tue, 16 Jul 2019 01:30:02 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-558293 In reply to Abhas Jain.

Not sure I understand your question, because hydrogen bonding shouldn’t affect the reaction. If you are referring to the fact that sugars exist as a mixture of linear and cyclic forms, this only starts becoming important for five-carbon sugars and above, and even then there is equilibrium between the open and closed chain forms. See this post on ring chain tautomerism: https://www.masterorganicchemistry.com/2017/07/13/pyranoses-and-furanoses-ring-chain-tautomerism-in-sugars/

]]> By: Abhas Jain https://www.masterorganicchemistry.com/2018/10/29/the-ruff-degradation-and-kiliani-fischer-synthesis/#comment-558130 Fri, 12 Jul 2019 18:10:46 +0000 https://www.masterorganicchemistry.com/?p=12066#comment-558130 In kiliani Fischer synthesis dont we take in account of H bonding in its cyclic form.

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