| abstract |
The present invention is directed to improved methods to synthesize oligonucleotide analogs having an acetal linkage, such as a 3',5'-formacetal (3'-O-CH2-O-5'),3',5'-thioformacetal (3'-S-CH2-O-5') or an analogous 2',5' linkage between adjacent nucleoside analog residues. Compositions comprising 5',3' and 2' phosphinate nucleoside analogs useful in the methods are also provided. |