A simple and efficient method for the preparation of eight phosphoramidite building blocks for incorporation of 2′-O-(2-aminoethoxymethyl) ribonucleosides and 2′-O-(3- aminopropoxymethyl) ribonucleosides into synthetic oligonucleotides has been developed. The synthetic routes are maximally convergent and provide sufficient amounts of phosphoramidites for several solid-phase synthesis coupling reactions. Using acyclic ...