Nucleoside phosphoramidites are used in the synthesis of oligonucleotides. Using a chemical approach allows quick and inexpensive access to custom-made oligonucleotides of the desired sequence. Enzymatic synthesis proceeds in a 5’ to 3’ direction, however the chemical synthesis is usually performed in the opposite direction. 5'-O-DMT-N2-isobutyryl-2'-O-(2-methoxyethyl)guanosine 3'-CE phosphoramidite, also known as DMT-2μ-O-Me-rG(ib) amidite, is a modified guanosine with a 2’-O-(2-methoxyethyl) group, these have been used in the synthesis of oligonucleotides as antisense drugs.
