The isomerization of D-glucose into D-fructose was investigated in view to afford carbohydrate source for the production of 5-hydroxymethylfurfural (HMF) without the use of toxic metallic catalyst. The process uses a basic heterogeneous catalyst in organic solvent mixtures to lead up to 72% selectivity of D-fructose for 68% conversion of D-glucose. The catalyst has been recycled four times with little decrease of the selectivity. The resulting carbohydrates solution can be directly dehydrated to afford HMF. (C) 2013 Elsevier B.V. All rights reserved.