5-methyl-1-[(2R,4R)-4-(trityloxymethyl)-3,6-dioxabicyclo[3.1.0]hexan-2-yl]pyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-3-hydroxy-4,5-bis(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4R,5R)-3,4-difluoro-5-(trityloxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-3-hydroxy-5-(hydroxymethyl)-4-(5-methyl-1,3,5-dithiazinan-2-yl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

(2S,3S,5R)-2-(hydroxymethyl)-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolane-3-carbonitrile

1-[(2R,3S,4S,5R)-3-azido-4-fluoro-5-(trityloxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,3aR,6aS)-3,4-dihydroxy-2,3,3a,4,6,6a-hexahydrofuro[2,3-c]furan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5R)-3-azido-4-fluoro-5-(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-4-azido-3-hydroxy-5-(trityloxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3R,4R,5R)-3-azido-4-hydroxy-5-(trityloxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-3-hydroxy-5-(hydroxymethyl)-4-(1,2,4-triazol-1-yl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-3-hydroxy-5-(hydroxymethyl)-4-pyrazol-1-yloxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3R,4R,5S)-4-azido-3-fluoro-5-(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3R,4R,5S)-4-azido-3-fluoro-5-(trityloxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,4S,5S)-5-(hydroxymethyl)-4-pyrazol-1-yloxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,4S,5S)-5-(hydroxymethyl)-4-(1,2,4-triazol-1-yl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione

1-[(2R,3S,4S,5S)-3-hydroxy-5-(hydroxymethyl)-4-imidazol-1-yloxolan-2-yl]-5-methylpyrimidine-2,4-dione