Synthesis of 2,3-O-benzyl-ribose and xylose and their equilibration

The preparation and NMR analysis of 2,3-di-O-benzyl d-ribose and 2,3-di-O-d-xylose are described. In DMSO-d6 the sugars adopt a conformation in which the hydroxyl groups are in an equatorial position. In CDCl3 and CD2Cl2 the sugars adopts a conformation in which intramolecular hydrogen bonding plays an important role in determining the equilibrium composition. These findings were also confirmed by DFT studies and, in the solid phase, by X-ray single crystal diffraction.

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2,3,-O-Dibenzyl-α,β-d-ribopyranoseC19H22O5Source of chirality: d-ribose[α]D23 = −19.6 (c 1.0, CHCl3)