Used in solid-phase oligonucleotide synthesis, this phosphoramidite building block enables the incorporation of adenosine with specific protecting groups that enhance coupling efficiency and stability during automated DNA/RNA synthesis. The 2'-O-TBDMS group protects the ribose 2'-hydroxyl in RNA strands, preventing unwanted side reactions and ensuring correct chain elongation. The N6-tert-butylphenoxyacetyl group stabilizes the adenine base during synthesis and is readily removed during final deprotection. The 5'-DMT group allows for monitoring of coupling success through colorimetric detection and supports stepwise chain assembly on solid support. The CE (cyanoethyl) group on the phosphate protects the phosphite moiety during synthesis and is removed under mild basic conditions. This compound is essential for producing high-purity antisense oligonucleotides, siRNA, and other therapeutic nucleic acids where precise modification and yield are critical.