Studies on nucleosides and nucleotides. LXXXVII. Purine cyclonucleosides. XLII. Synthesis of 2'-deoxy-2'-fluoroguanosine.

2'-Deoxy-2'-fluoroguanosine (VII) was synthesized starting from 8, 2'-anhydro-8-oxy-9-β-D-arabinofuranosylguanine (8, 2'-O-cycloguanosine) (I). Compound I was protected at 2-NH2 with an isobutyryl group and at 3'- and 5'-OH with tetrahydrofuranyl groups. The protected compound III was derivatized to the arabino nucleoside V and thence converted to VII by treatment with trifluoromethanesulfonyl chloride and tetra-n-butylammonium fluoride. The resulting 2'-deoxy-2'-fluoroguanosine showed a 3'-endo favored conformation.