70849-22-8Relevant articles and documents
Phosphate-catalyzed degradation of d-glucosone in aqueous solution is accompanied by C1-C2 transposition
Zhang, Wenhui,Serianni, Anthony S.
, p. 11511 - 11524 (2012/08/28)
Pathways in the degradation of the C6 1,2-dicarbonyl sugar (osone) d-glucosone 2 (d-arabino-hexos-2-ulose) in aqueous phosphate buffer at pH 7.5 and 37 °C have been investigated by 13C and 1H NMR spectroscopy with the use of singly and doubly 13C-labeled isotopomers of 2. Unlike its 3-deoxy analogue, 3-deoxy-d-glucosone (3-deoxy-d-erythro-hexos-2-ulose) (1), 2 does not degrade via a 1,2-hydrogen shift mechanism but instead initially undergoes C1-C2 bond cleavage to yield d-ribulose 3 and formate. The latter bond cleavage occurs via a 1,3-dicarbonyl intermediate initially produced by enolization at C3 of 2. However, a careful monitoring of the fates of the sketetal carbons of 2 during its conversion to 3 revealed unexpectedly that C1-C2 bond cleavage is accompanied by C1-C2 transposition in about 1 out of every 10 transformations. Furthermore, the degradation of 2 is catalyzed by inorganic phosphate (Pi), and by the Pi-surrogate, arsenate. C1-C2 transposition was also observed during the degradation of the C5 osone, d-xylosone (d-threo-pentose-2- ulose), showing that this transposition may be a common feature in the breakdown of 1,2-dicarbonyl sugars bearing an hydroxyl group at C3. Mechanisms involving the reversible formation of phosphate adducts to 2 are proposed to explain the mode of Pi catalysis and the C1-C2 transposition. These findings suggest that the breakdown of 2 in vivo is probably catalyzed by Pi and likely involves C1-C2 transposition.
Paramolybdate anion-exchange resin, an improved catalyst for the C-1-C-2 rearrangement and 2-epimerization of aldoses.
Clark Jr.,Hayes,Barker
, p. 263 - 270 (2007/10/02)
Aqueous solutions of molybdate at 90 degrees bring about the inversion of the C-1-C-2 fragment of aldoses having four or more carbon atoms, generating thermodynamically equilibrated mixtures of the starting aldose and its 2-epimer. In some cases, notably with the aldopentoses, substantial proportions of the 3-epimers are produced, as well as 2-epimers that have not undergone inversion of the C-1-C-2 fragment. These side-reactions can be controlled by using the paramolybdate form of an anion-exchange resin (AG MP-1) together with the formate form of the same resin. The latter acts to scavenge unbound molybdate and paramolybdate anions that appear to be responsible for the side reactions.