Used in solid-phase oligonucleotide synthesis, this phosphoramidite building block enables the site-specific incorporation of a modified uridine derivative into DNA strands. The trifluoroacetylamino group provides a protected reactive handle for post-synthetic modifications, allowing conjugation with labels, probes, or functional groups after oligonucleotide assembly. The DMT (dimethoxytrityl) group ensures proper monitoring of coupling efficiency during synthesis, while the CE phosphoramidite moiety ensures high coupling yields on DNA synthesizers. This modification is particularly useful in developing functional nucleic acids for diagnostics, antisense technologies, and fluorescent probes, where precise placement of detectable or reactive groups is required. The E-propenyl linker adds rigidity and defined spacing, improving hybridization properties and signal detection in probe applications.