Dithiophosphoric acid O-[(2R,3R,4R,5R)-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-hydroxymethyl-4-(tetrahydro-pyran-2-yloxy)-tetrahydro-furan-3-yl] ester S,S'-diphenyl ester

O5'-(4-methoxy-trityl)-O2'-tetrahydropyran-2-yl-uridine