tert-butyl ((S)-1-(((Z)-((3S,4R,5R)-5-(3-((benzyloxy)methyl)-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-bis((tert-butyldimethylsilyl)oxy)dihydrofuran-2(3H)-ylidene)methyl)amino)-1-oxopropan-2-yl)carbamate