Epimerization of Aldoses Catalyzed by Dioxobis (2, 4-pentanedionato-O, O')-molybdenum (VI). An Improved Procedure for C-2 Epimer Preparation

Abstract

Epimerization of aldo-hexoses and -pentoses to the corresponding C-2 epimers Proceeds more rapidly when catalyzed by dioxobis (2, 4-pentanedionato-O, O') molybdenum (VI) in N, N-dimethylformamide than in the reported reaction with aqueous molybdic acid. Thus, on treatment at 50° for 5 hr, D-glucose or D-mannose gave an equilibrium mixture of D-glucose and D-mannose in a ratio of 55 : 45.