合成路线1

Reaction of 1,2:5,6-di-O-isopropylidene-3-O-tosyl-a-D-allofuranose (I) with KF in acetamide at 210 oC gives 3-deoxy-3-fluoro-1,2:5,6-di-O-isopropylidene-a-D-glucofuranose (II), which is treated with a 1:1 mixture of metha-nol and 0.7% aqueous H2SO4 to yield 3-deoxy-3-fluoro-1,2-isopropylidene-a-D-glucofuranose (III). Selective acylation of the sugar (III) with benzoyl chloride in pyridine affords the 6-O-benzoyl derivative (IV), which is treated with Amberlite IR-100 (H+) ion-exchange resin in hot dioxane to provide 6-O-benzoyl-3-deoxy-3-fluoro-D-glucofuranose (V). The oxidative cleavage of glucofuranose (V) by means of KIO4 in water results in rearrangement to give 5-O-benzoyl-2-deoxy-2-fluoro-3-O-formyl-D- arabinofuranose (VI), which is deformylated by means of NaOMe in methanol to provide 5-O-benzoyl-2-deoxy-2-fluoro-D-arabinofuranose (VII). Acylation of the arabinofuranose (VII) with acetic anhydride in pyridine affords the 1,3-di-O-acetyl derivative (VIII), which is treated with HBr in AcOH/CH2Cl2 to yield 3-O-acetyl-5-O-benzoyl-2-deoxy-2-fluoro-D-arabinofuranosyl bromide (IX) (1). Condensation of compound (IX) with 2-chloroadenine (X) by means of potassium tert-butoxide in different solvents gives the acylated 2-chloroadenosine derivative (XI), which is finally deacylated by means of NaOMe in methanol.