Dithiophosphoric acid O-{(3aR,4R,6R,6aR)-6-[6-imino-1-(2-{2-[(4-methoxy-phenyl)-diphenyl-methoxy]-ethoxy}-ethyl)-1,6-dihydro-purin-9-yl]-2,2-dimethyl-tetrahydro-furo[3,4-d][1,3]dioxol-4-ylmethyl} ester S,S'-diphenyl ester

5-[(methoxymethylene)amino]-1-[5-O-(tert-butyldimethylsilyl)-2,3-O-(isopropylidene)-β-D-ribofuranosyl]imidazole-4-nitrile