Improvements in the phosphoramidite procedure for the synthesis of oligodeoxyribonucleotides

The paper describes an improved method for the synthesis of oligodeoxyribonucleotides using phosphoramidite chemistry. Our procedure relies on novel phosphoramidite intermediates, the deoxyribonucleoside-3'-morpholine-methoxyphosphins. These compounds are extremely stable and can be purified readily. Condensation reactions during solid-phase synthesis can thus be performed with high efficiency and result in a high yield synthesis of long chain oligodeoxyribonucleotides.