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Studies in Fructofuranose Chemistry.

The glycolytic pathway enzyme phosphofructokinase (E.C. 2.7.1.11) has as its substrate and activator two different carbohydrate phosphate esters. Both are derivatives of D-fructose in the furanose ring form. This dissertation is divided into two chapters: the first deals with the conformational specificity of the active site and the second the structure of the activator. The compound 2,5-anhydro-3,4-0-(1,2-ethanediyl)-D-mannitol was designed to test the active site. The synthesis utilized a phase-transfer cyclo-dialkylation of a vicinal diol to yield a trans-fused 2,5,8-trioxabicyclo[4.3.0]nonane system. The final product was shown to exist in a locked conformation in solution by temperature dependent n.m.r. experiments which showed no line shape change. The data indicate that the five-membered ring is locked by the trans-fused six-membered 1,4-dioxane ring into a twist 4T3 conformation. A single crystal X-ray study was carried out. The crystalline product exists in an ideal twist conformation with a pseudorotation angle of 0° and amplitude of 47.2° in agreement with the n.m.r. results. The compound, as the monophosphate, is intended to verify the linear plot of substrate efficacy index versus P~4T3 concentration observed with several ketose 6-phosphates.