SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF 3-DEOXY-3-FLUORO-BETA-D-ALLOPYRANOSIDE

The synthesis of a novel compound, 3-deoxy-3-fluoro-beta-D-allopyranos ide, is described. It involves blocking the 4- and 6-positions of allo se to cause fluorination only at the 3-position. This six-step synthes is gave pure crystalline compound in a 5% overall yield. The crystal s tructure, determined by X-ray diffraction, confirmed the chemical form ula and configuration of the product. It showed that the C-F bond is a xial, while the C-(OH) bonds are equatorial. The overall conformation of this fluoroallose is similar to that of allose (Acta Cryst. 1984, C 40, 1863) (with OH instead of F), but the packing in the two crystals is different in the region of C3, the site of chemical variation.