1-[10-azido-2,3-di-O-(tert-butyldimethylsilyl)-6,10,11-trideoxy-8,9-O-isopropylidene-11-phenylsulfinyl-L-galacto-D-allo-undecofuranosyl-(1,4)]uracil

acetic acid 2-(7-azido-2,2-dimethyl-6-phenylsulfanyl-tetrahydro-[1,3]dioxolo[4,5-c]pyran-4-yl)-1-[3,4-bis-(tert-butyl-dimethyl-silanyloxy)-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-tetrahydro-furan-2-yl]-ethyl ester