Conversion of 5-hydroxymethylfurfural to furan-2,5-dicarboxylic acid by a simple and metal-free catalytic system.

A simple and metal-free catalytic system composed of NaO t Bu/DMF and an O 2 balloon efficiently converted 5-hydroxymethylfurfural (5-HMF) to furan-2,5-dicarboxylic acid with an 80.85% yield. 5-HMF analogues and various types of alcohols were also transformed to their corresponding acids in satisfactory to excellent yield by this catalytic system.