Synthesis of the phosphoramidite derivatives of 2'-deoxy-2'-C-alpha-methylcytidine and 2'-deoxy-2'-C-alpha-hydroxymethylcytidine: analogues for chemical dissection of RNA's 2'-hydroxyl group.

Oligonucleotides containing 2'-C-alpha-methyl and 2'-C-alpha-hydroxymethyl modifications enable strategies for delineation of the distinctive role fulfilled by the 2'-hydroxyl group in RNA structure and function. Synthetic routes to the phosphoramidite derivatives of 2'-deoxy-2'-C-alpha-methylcytidine (14%, 15 steps) and 2'-deoxy-2'-C-alpha-hydroxymethylcytidine (19%, 10 steps) from methyl 3,5-di-O-(4-chlorobenzyl)-alpha-d-ribofuranoside are developed.