Talk:Ketose

Ketose reducing?
Why are ketoses reducing? julianna What　I am usually told is that the carbonyl group cutting through a carbon chain is no reducing.......

plx give me the mechanism... —Preceding unsigned comment added by 58.152.219.35 (talk) 12:24, 14 March 2007


 * I believe since ketoses contain a carbonyl group, which are highly acidic, acts a hydrogen donor reducing its corresponding acceptor. LostLucidity (talk) 17:39, 12 March 2008 (UTC)


 * 58.152.219.35, I think you are referring to either Tollens' test or the Fehling test, both of which are performed in a basic reagent. In these circumstances ketoses can be converted to aldoses (this is called the Lobry-de Bruyn-van Ekenstein transformation). In the case of D-fructose you get D-glucose and D-mannose. Finally, these aldoses are easily reduced. Per Le Châtelier's principle almost all of the sugar will react, i.e. the test succeeds. This is what I have been taught. --62.224.90.35 (talk) 00:00, 9 April 2008 (UTC)

Shouldn't we clarify it in the text. The sentence: "Ketoses can isomerize into an aldose when the carbonyl group is located at the end of the molecule" is ambiguous.--kupirijo (talk) 09:18, 24 October 2008 (UTC)


 * OK, it's about a decade late, but I've added the answer to this question into the article. Ketoses and aldoses can turn into each other through tautomerization. --Slashme (talk) 22:45, 18 November 2017 (UTC)
 * The article now says "...can tautomerize into aldoses via an aldol intermediate", but ketoses and aldoses are aldols, so what does this mean? --FredV (talk) 10:01, 12 June 2019 (UTC)