1-((2R,4R,5R)-5-{2-[(1,1-Diethoxy-ethyl)-methyl-phosphinoyl]-ethyl}-4-hydroxy-tetrahydro-furan-2-yl)-5-methyl-1H-pyrimidine-2,4-dione

1-((2R,4S,5R)-4-hydroxy-5-(2-((((2S,3S,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)methyl)(methyl)phosphoryl)ethyl)tetrahydrofuran-2-yl)-5-methylpyrimidine-2,4(1H,3H)-dione