3-2',3',5'-tri-O-benzyl-β-D-ribofuranosyl-2-(2-furyl)pyrido<1,2-a>pyrimidin-4-one

3-2',3',5'-tri-O-benzyl-β-D-ribofuranosyl-2-ethoxypyrido<1,2-a>pyrimidin-4-one

3-2',3',5'-tri-O-benzyl-β-D-ribofuranosyl-2-ethoxy-9-methylpyrido<1,2-a>pyrimidin-4-one

1-2',3',5'-tri-O-benzyl-β-D-ribofuranosyl-1-chloro-2-(3-methyl-2-pyridylamino)ethylene

2-ethoxy-3-(β-D-ribofuranosyl)-9-methylpyrido<1,2-a>pyrimidin-4-one