Starting from HEH (species 5-5), sequential 1,4-conjugated elimination reactions remove two water molecules to form species 7-3. Hydrogen migration within species 7-3 results in a symmetric diketone diol intermediate (8-3). Two double-water catalyzed reactions facilitate cyclization and a further water elimination to produce HMF. The transformation of 8-3 to 9-1 is a ring closure with an extremely long distance proton transfer (5 bonds separate the proton donor and acceptor, Fig. ). The dehydration step similarly involves a proton and hydroxyl separated by 5 bonds (Fig. ). These long distance proton transfers use two external water molecules as a bridge for proton-shuttling, resulting in low catalyzed activation energies of 29.66 and 20.87 kcal/mol, respectively. Based on this new pathway, we predict that the rate limiting step of HMF formation is the isomerization from D-glucose to D-Psicose with an overall barrier of 30.98 kcal/mol.