Antal M J, Mok W S, Richards G N
Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu 96822.
Carbohydr Res. 1990 May 15;199(1):91-109. doi: 10.1016/0008-6215(90)84096-d.
The literature contains two alternative hypotheses for the mechanism of dehydration of fructose to 5-(hydroxymethyl)-2-furaldehyde (HMF), namely (1) a sequence of reactions commencing with and retaining the fructofuranose ring intact, and (2) a succession of reactions proceeding mainly via open-chain intermediates. The existing evidence for hypotheses (1) and (2) is reviewed and found to favor (1). The major products from fructose in water at 250 degrees, (with and without acid catalysis) have been investigated on a time-resolved basis and analysis of the results was found to confirm the first hypothesis. A necessary fructofuranosyl-cation intermediate in this hypothesis is produced directly by the hydrolysis of sucrose, and reacts to produce HMF in high yields.
文献中关于果糖脱水生成5-(羟甲基)-2-糠醛（HMF）的机制存在两种不同的假设，即：（1）一系列反应从保留完整的呋喃果糖环开始并保持其完整；（2）一系列主要通过开链中间体进行的反应。对假设（1）和（2）的现有证据进行了综述，发现支持（1）。在250℃的水中（有无酸催化），对果糖的主要产物进行了时间分辨研究，结果分析证实了第一个假设。该假设中必要的呋喃果糖基阳离子中间体直接由蔗糖水解产生，并高产率地反应生成HMF。
