Synthesis and Antiviral Evaluation of 2′-Deoxy-4′-thio-L-nucleosides and Their Phosphotriester Derivatives BearingS-Acyl-2-thioethyl Bioreversible Phosphate-Protecting Groups

Thiosugars. VIII. Preparation of new 4'-thio-L-lyxo pyrimidine nucleoside analogues

Reaction of 1-O-acetyl-2,3,5-tri-O-benzyl-4-thio-L-lyxofuranose with silylated pyrimidine bases and subsequent deprotection with boron tribromide led to 4'-thio-L-lyxo pyrimidine nucleosides. The 5-bromo-6-methyl derivative was prepared from methyl 2,3,5-tri-O-acetyl-4-thio-L-lyxofuranoside. Deacetylation was performed with sodium methoxide. The anomers were separated by HPLC and their configurations assigned by NMR spectroscopy and X-ray structural analyses. The biological activity of the nucleosides was tested.

Thiosugars. Part 9: synthesis and biological evaluation of some 4'-thio-L-arabino nucleoside analogues

1-O-Acetyl-2,3,5-tri-O-benzyl-4-thio-L-arabinofuranose (10) was transformed into the corresponding cytidine derivative 9 and the adenosine derivative 12. Both nucleosides, as well as the previously reported uridine and thymidine analogues 2 and 3, were tested for their in vitro antiviral activity.