ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Reactions of Saccharides Catalyzed by Molybdate Ions. IV.* Epimerization of Aldopentoses

V. Bílik

Institute of Chemistry t Slovak Academy of Sciences, Bratislava 9

Abstract:  Epimerization of aldopentoses in water solution catalyzed by molybdenic acid leads to the formation of equilibrium mixtures of all four aldopentoses. In the equilibrium mixture, which is characteristic for each epimeric pair of pentoses (D-arabinose : D-ribose — 6 3, D-xylose : D-lyxose — 10 9), the epimer having trans arrangement of the C-2 and C-3 hydroxyl groups predominates. Small amounts of the complementary pair of epimeric pentoses in the equilibrium mixture are explained by the inversion of the hydroxyl group at C-3 due to the formation of the molybdate complex with the hydroxyl groups at C-2 and C-4 of D-ribose and D-xylose in the conformation 1С.

Full paper in Portable Document Format: 264a372.pdf

Chemical Papers 26 (4) 372–375 (1972)