Abstract
Ribosylation of 2-thioxo-5,6,7,8-tetrahydrobenzo thieno[2,3-d]pyrimidin-4(3H)-one 1a and 2,4-dithioxo-5,6,7,8-tetrahydrobenzo thieno[2,3-d]pyrimidine 1b with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose 7 afforded the benzoylated S-nucleoside derivatives 3 and 4, respectively. Debenzoylation of 3 and 4 by using methanolic sodium methoxide yielded the corresponding free S-nucleosides 5 and 6, respectively. Furthermore, the reaction of potassium salt of 2-thioxo-5,6,7,8-tetrahydrobenzo thieno[2,3-d]pyrimidin-4(3H)-one 8 with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide 9, afforded 10. Deacetylation of the latter by using methanolic sodium methoxide yielded the corresponding S-glycoside, 2-(2′,3′,4′,6′-tetra-hydroxy-β-D-glucopyranosylthio)-5,6,7,8-tetrahydro-benzothieno [2,3-d]pyrimidin-4-one 11. The structural elucidation of the new nucleosides formed was reported.