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

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

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