NUCLEAR MAGNETIC RESONANCE STUDIES OF D-ERYTHROSE 4-PHOSPHATE IN AQUEOUS SOLUTION. STRUCTURES OF THE MAJOR CONTRIBUTING MONOMERIC AND DIMERIC FORMS

Article abstract of DOI:10.1016/S0008-6215(00)85292-1

N.m.r. studies show that a concentrated (ca. 1.0 M ) aqueous solution of D-erythrose 4-phosphate is composed of an equilibrium mixture of the monomeric aldehyde and hydrated aldehyde forms, which interconvert rapidly, together with a major contribution from three dimeric forms.In dilute solutions (ca. 0.04 M ), the hydrated monomer is predominant and dimeric forms are not detectable at this concentration.The chemical structures and stereochemistry of the three dimers have been elucidated by (1)H- and (13)C n.m.r. spectroscopy of D-erythrose 4-phosphate and its (4,4-²H₂) and (3,4,4'-²H₃) derivatives, aided by the use of the model compounds, glycolaldehyde, D-glyceraldehyde, and DL-glyceraldehyde 3-phosphate, which also form dimers in concenrated aqueous solution.In some cases, the tert-butyldimethylsilyl derivatives of the model dimeric compounds were prepared and isolated.The two major dimers of D-erythrose 4-phosphate, I and II are asymmetrically substituted 1,3-dioxane and 1,3-dioxolane stuctures, respectively, and dimer III is the α anomer of dimer I.