[(2R,3S,5R)-5-[4-amino-5-(hydroxymethyl)-2-oxopyrimidin-1-yl]-3-hydroxyoxolan-2-yl]methyl phosphate [(2R,3S,5R)-5-[4-amino-5-(hydroxymethyl)-2-oxo-pyrimidin-1-yl]-3-hydroxy-tetrahydrofuran-2-yl]methyl phosphate [(2R,3S,5R)-5-[4-amino-5-(hydroxymethyl)-2-oxo-1-pyrimidinyl]-3-hydroxy-2-tetrahydrofuranyl]methyl phosphate [(2R,3S,5R)-5-(4-amino-2-keto-5-methylol-pyrimidin-1-yl)-3-hydroxy-tetrahydrofuran-2-yl]methyl phosphate [(2R,3S,5R)-5-[4-amino-5-(hydroxymethyl)-2-oxo-pyrimidin-1-yl]-3-hydroxy-oxolan-2-yl]methyl phosphate