SYNTHESIS OF DEOXY, DIDEOXY AND DIDEHYDRODIDEOXY ANALOGS OF 9-(BETA-D-HEXOFURANOSYL)ADENINE

Condensation of ,2-di-O-acetyl-3,5,6-tri-O-benzoyl-D-glucofuranose wit h N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleo side I. Partial deacetylation of I, followed by mesylation, gave -2-0- methanesulfonyl-beta-D-glucofuranosyl)adenine (III). esulfonyl-beta-D- glucofuranosyl)-N6-benzoyladenine (IV) was prepared by condensation of tetra-0-acetyl-3-0-methanesulfonyl-D-glucofuranose with N6-benzoylade nine. Reaction of mesyl derivative III with methanolic sodium methoxid e and of mesyl derivative IV with methanolic ammonia led to 2',3'-anhy dronucleosides V and VI which were acetylated to give the respective O -acetyl-2,3-anhydro-beta-D-mannofuranosyl)adenine (VII) and -O-acetyl- 2,3-anhydro-beta-D-allofuranosyl)adenine (VIII). Epoxy derivative VII was cleaved with bromotrimethylsilane, affording a mixture of etyl-2-b romo-2-deoxy-beta-D-glucofuranosyl)adenine (Xa) and etyl-3-bromo-3-deo xy-beta-D-altrofuranosyl)adenine (XIa), epoxy derivative VIII was clea ved analogously to give etyl-3-bromo-3-deoXy-beta-D-glucofuranosyl)ade nine (XIIa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-beta-D-arabino-hexofuranosyl)adenine (Xc), 9-(3-deoxy-beta-D-arabino-hexofuranosyl)adenine (XIc) and 9-(3-d eoxy-beta-D-ribo-hexofuranosyl)adenine (XIIc). etyl-3-bromo-3-deoxy-be ta-D-glucofuranosyl)adenine (XIId), which was prepared by acetylation of XIIa, on reductive elimination with Cu/Zn couple and subsequent dea cetylation gave -dideoxy-beta-D-erythro-hex-2-enofuranosyl)adenine (XI V). -(2,3-Dideoxy-beta-D-erythro-hexofuranosyl)adenine (XVI) was obtai ned either by catalytic hydrogenation of bromo derivative XIId followe d by deacetylation, or by catalytic hydrogenation of didehydro derivat ive XIV. The synthesized nucleosides were tested for antiviral activit y.