One-pot synthesis of modified DNA oligomers by novel glycosidation using nucleic acids

We demonstrate the novel glycosidations using a nucleic acid base (A or G) as a leaving group of glycosyl donors and the one-pot synthesis of modified DNA oligomers using this glycosidation method. It was found that the glycosidations of guanosine and adenosine with alcohols using MeOTf as an alkylative agent or TfOH as a protic acid in DMSO effectively proceeded to give the corresponding glycosides in high yields, while cytidine and thymidine could not be activated under these conditions. Furthermore, it was found that DNA oligomers could be converted into DNA oligomer analogs, which were selectively modified at the purine base positions, by this glycosidation method in one step.