NEW SYNTHETIC ROUTES TO PROTECTED PURINE 2'-O-METHYLRIBOSIDE-3'-O-PHOSPHORAMIDITES USING A NOVEL ALKYLATION PROCEDURE

A highly selective alkylation procedure has been developed enabling new synthetic routes to be established for protected purine 2′-O-methylriboside- 3′-O-phosphoramidites; building blocks for the assembly of 2′-O-methyloligoribonucleotides. The new procedure avoids the use of the highly toxic and potentially explosive reagent diazomethane and is far superior to the use of silver oxide/methyl iodide. Moreover, the use of highly versatile key intermediates will enable the synthesis of a wide variety of base modified analogues as well as other 2′-O-alkylriboside derivatives. © 1990 Oxford University Press.