Used in solid-phase oligonucleotide synthesis as a phosphoramidite building block for introducing modified sugar moieties into DNA or RNA strands. Its structure enables selective protection and coupling efficiency, making it valuable in the preparation of antisense oligonucleotides, siRNA, and other therapeutic nucleic acids. The presence of the bis(4-methoxyphenyl)(phenyl)methoxy group acts as an acid-labile protecting group, allowing for controlled deprotection during synthesis. The 2-cyanoethyl group stabilizes the phosphite intermediate and prevents side reactions, while the diisopropylamino moiety serves as a leaving group during coupling. Widely applied in automated synthesizers for high-yield, high-purity oligonucleotide production used in research, diagnostics, and drug development.