1-((2R,3S,3aR,9aR)-3-Bromo-5,5,7,7-tetraisopropyl-tetrahydro-1,4,6,8-tetraoxa-5,7-disila-cyclopentacycloocten-2-yl)-3-nitro-1H-pyrimidine-2,4-dione

3-Nitro-1-((1R,2R,4R,5R)-4-trityloxymethyl-3,6-dioxa-bicyclo[3.1.0]hex-2-yl)-1H-pyrimidine-2,4-dione

Trifluoro-methanesulfonic acid (2R,3R,4S,5R)-4-chloro-5-(3-nitro-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-trityloxymethyl-tetrahydro-furan-3-yl ester

Trifluoro-methanesulfonic acid (2R,3R,4S,5R)-4-bromo-5-(3-nitro-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-2-trityloxymethyl-tetrahydro-furan-3-yl ester