Propionic acid (2R,5S)-5-(tert-butyl-dimethyl-silanyloxymethyl)-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2,5-dihydro-furan-3-yl ester

1-{(2R,5S)-5-(tert-Butyl-dimethyl-silanyloxymethyl)-4-[2-methyl-prop-(E)-ylidene]-3-oxo-tetrahydro-furan-2-yl}-1H-pyrimidine-2,4-dione

1-[(2R,3S)-5-(tert-Butyl-dimethyl-silanyloxymethyl)-3-hydroxy-2,3-dihydro-furan-2-yl]-1H-pyrimidine-2,4-dione

Acetic acid (2R,3S)-5-(tert-butyl-dimethyl-silanyloxymethyl)-2-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2,3-dihydro-furan-3-yl ester

1-[(2R,5S)-5-(tert-Butyl-dimethyl-silanyloxymethyl)-4-eth-(E)-ylidene-3-oxo-tetrahydro-furan-2-yl]-1H-pyrimidine-2,4-dione