Dinucleotide Synthesis via Phosphoramidite Coupling - Reaction Mechanism Explained #3510249 (License: Personal Use)

The image depicts a classic solid-phase oligonucleotide synthesis pathway where nucleoside 1 is first phosphitylated to give intermediate 3, then activated with tetrazole to form reactive phosphite 4. This couples with the 5′-OH of nucleoside 5 (bearing B² and OAc protecting groups) to form a phosphite triester linkage, which is subsequently oxidized to the stable phosphate diester in product 6. Protecting groups (RO, B¹, B², OBn, OAc) ensure regioselectivity and prevent side reactions.

Used in biochemistry and molecular biology educational resources, synthetic oligonucleotide protocol guides, and pharmaceutical development documentation; matches user intent for understanding nucleic acid synthesis mechanisms or troubleshooting solid-phase DNA/RNA assembly.