1-[(5E)-6-[Bis[(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-5,6-dideoxy-2-O-methyl-β-D-ribo-hex-5-enofuranosyl]-2,4(1H,3H)-pyrimidinedione

1-[(5Z)-6-[Bis[(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]-5,6-dideoxy-2-O-methyl-β-D-ribo-hex-5-enofuranosyl]-2,4(1H,3H)-pyrimidinedione

1-[(5E)-6-[Bis[(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]-5,6-dideoxy-2-O-methyl-β-D-ribo-hex-5-enofuranosyl]-2,4(1H,3H)-pyrimidinedione

1-[(5Z)-6-[Bis[(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]-5,6-dideoxy-3-O-[(1,1-dimethylethyl)dimethylsilyl]-2-O-methyl-β-D-ribo-hex-5-enofuranosyl]-2,4(1H,3H)-pyrimidinedione

1-[(5E)-6-[Bis[(2,2-dimethyl-1-oxopropoxy)methoxy]phosphinyl]-5,6-dideoxy-3-O-[(1,1-dimethylethyl)dimethylsilyl]-2-O-methyl-β-D-ribo-hex-5-enofuranosyl]-2,4(1H,3H)-pyrimidinedione