Synthesis of 5'-C-and 2'-O-(Bromoalkyl)-Substituted Ribonucleoside Phosphoramidites for the Post-synthetic Functionalization of Oligouncleotides on Solid Support

摘要

The preparation of building blocks for the incorporation of 6'-O-(5-bromopenty)-substituted #beta#-D-allofuranosylnucleosides and 2'-O-[(3-bromopropoxy)methyl]-substituted ribonucleosides into oligonucleotide sequences is presented (Schemes 1 and 2). These reactive building blocks can be modified with a variety of soft nucleophiles while the (full protected)sequence is still attached to the solid support. As an example of this strategy, we carried out some preliminary solid-phase substitution and conjugation reactions with DNA sequences containing a 2'-O-[(3-bromopropoxy)methyl]-substituted ribonucleoside (Scheme 3)and determined the pairing properties of duplexes obtained therefrom.