With the current heightened interest in DNA sequencing, it is probably timely to remember the potential of the segmented synthesis technique in which many oligonucleotides can be prepared simultaneously. A recent paper1 applies H-phosphonate chemistry to this technique. The resulting oligonucleotides are prepared rapidly and efficiently, reminding us again of the simplicity and efficiency of H-phosphonate chemistry. The authors also describe a key advantage of H-phosphonate monomers in that excess activated monomer can be simply regenerated by hydrolyis and purified for re-use. The monomers are shown to be active and unmodified by the regeneration process.
