The alcohol group of hydroxymethylfurfural (compound 1, HMF) is preferentially oxidized by dioxygen and metal/bromide catalysts [Co/Mn/Br, Co/Mn/Zr/Br; Co/Mn=Br/(Co+Mn) = 1.0 mol/mol] to form the dialdehyde, 2,5-diformylfuran (compound 2, DFF) in 57% isolated yield. HMF can be also oxidized, via a network of identified intermediates, to the highly insoluble 2,5-furandicarboxylic acid (compound 5, FDA) in 60% yield. For comparison, benzyl alcohol gives benzaldehyde in 80% using the same catalyst system. Over-oxidation (to CO₂) of HMF is much higher than that of the benzyl alcohol but can be greatly reduced by increasing catalyst concentration.

中文翻译：

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5-羟基甲基糠醛的催化空气氧化合成2,5-二甲酰基呋喃和呋喃-2,5-二羧酸。金属溴化催化剂意外地将苄醇选择性好氧氧化为苯甲醛

羟甲基糠醛（化合物1，HMF）的醇基优先被双氧和金属/溴化物催化剂[Co / Mn / Br，Co / Mn / Zr / Br; Co / Mn ＝ Br /（Co + Mn）＝ 1.0mol / mol]形成二醛2，5-二甲酰基呋喃（化合物2，DFF），分离产率为57％。HMF也可以通过已确定的中间体网络氧化为高度不溶的2,5-呋喃二甲酸（化合物5，FDA），产率为60％。为了进行比较，使用相同的催化剂体系，苯甲醇可生成80％的苯甲醛。HMF的过氧化（转化为CO ₂）远高于苯甲醇，但可以通过提高催化剂浓度来大大降低。