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

1-[(2R,3S,4S,5R)-3-azido-4-fluoro-5-(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,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