摘要 |
<p>Method for the preparation of natural or synthetic nucleosides, nucleoside analogues or oligonucleotides composed of at least two such nucleosides and/or nucleoside analogues, whose basic structure contains an optionally substituted radical of a nucleoside base B and a protected hydroxyl group of the formula R1-O- in which R1 is a protective group, or which are bonded via the oxygen atom of a hydroxyl group directly or via a bridging group to a solid carrier material, from nucleoside monomers or from oligonucleotides to whose basic structure, besides said radicals, a group of the formulae I, Ia or Ib …<IMAGE>… is bonded, by converting the group of the formulae I, Ia or Ib into a hydroxyl group -OH by reacting the nucleosides or oligonucleotides, where appropriate in an inert organic solvent, with an excess of an aliphatic, cycloaliphatic, araliphatic or aromatic alcohol with 1 to 30 C atoms, a polyol with 2 to 50 C atoms or a polymeric polyol in the presence of at least a catalytic amount of an inorganic base or of an organic nitrogen base, the base having a pK of 4 to 10.</p> |