Collect. Czech. Chem. Commun. 1994, 59, 1654-1664
https://doi.org/10.1135/cccc19941654

Synthesis of Deoxy, Dideoxy and Didehydrodideoxy Analogs of 9-(4-C-Hydroxymethyl-α-L-pentofuranosyl)adenine

Hubert Hřebabecký and Antonín Holý

Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague 6, Czech Republic

Abstract

Condensation of 1,2-di-O-acetyl-3,5-di-O-benzoyl-4-C-benzoyloxymethyl-L-arabinofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I, which upon partial deacetylation and subsequent mesylation was converted into 9-(3,5-di-O-benzoyl-4-C-benzoyloxymethyl-2-O-methanesulfonyl-α-L-arabinofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-α-L-arabinofuranosyl)-N6-benzoyladenine (V) was obtained by condensation of 1,2,5-tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-L-arabinose with N6-benzoyladenine. Reaction of mesyl derivatives III and V with methanolic sodium methoxide afforded 2',3'-anhydro nucleosides VIa and VIIa, which were acetylated to give 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-ribofuranosyl)adenine (VIb) and 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-lyxofuranosyl)adenine (VIIb). Epoxy derivative VIb was cleaved with bromotrimethylsilane to 9-(5-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIIa); the same reaction with epoxy derivative VIIb afforded a mixture of 9-(5-O-acetyl-4-C-acetoxymethyl- 2-bromo-2-deoxy-α-L-xylofuranosyl)adenine (IXa) and 9-(5-O-acetyl-4-C-acetoxymethyl-3-bromo- 3-deoxy-α-L-arabinofuranosyl)adenine (Xa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-4-C-hydroxymethyl-α-L-erythro-pentofuranosyl)adenine (VIIIc), 9-(2-deoxy-4-C-hydroxymethyl- α-L-threo-pentofuranosyl)adenine (IXc) and 9-(3-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)adenine (Xc). 9-(2,5-Di-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIId), prepared by acetylation of VIIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation afforded 9-(2,3-dideoxy-4-C-hydroxymethyl-α-L-glycero-pent-2-enofuranosyl)adenine (XIb). 9-(2,3-Dideoxy-4-C-hydroxymethyl-α-L-glycero-pentofuranosyl)adenine (XIIb) was obtained either by catalytic hydrogenation of bromo derivative VIIId, followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIb. The nucleosides synthesized were tested for antiviral activity.