The following question was sent to me .The question is " Which of the following is A ?"
The given answer was a,b,c
Background
If both ends of an aldose chain are oxidized to carboxylic acids the product is called an aldaric acid.
source : https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/carbhyd.htm#carb2
My thoughts
- Options a and c are direct reactions.
- Option b gives 2 and it can only rotated in the plane it is drawn (2D) by 180 degrees (http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch07/ch7-7.html) to give 1.
- How ever option d in acidic medium could tautomerise to give 3d , that on oxidation again gives 1.
Therefore answer should be a,b,c,d.
My answer hinges on tautomerisation of ketone is acidic medium. Would this compound (3R,4S,5R)-1,3,4,5,6-pentahydroxyhexan-2-one tautomerise in nitric acid ?
Any help in this regard is very much appreciated. Thankyou.
reference :
1 http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch07/ch7-7.html