Method for production of 2'-O-derivatized uridine and cytosine RNA synthons comprising derivatizing the 2'-hydroxyl group of a partially protected cytosine ribonucleoside to preferentially produce a partially protected 2'-O-derivatized nucleoside, which is then either (1) reacted at the 3'-hydroxyl group to produce a 2'-O-derivatized cytosine RNA synthon, or (2) reacted with a hydroxide source to produce a uridine nucleobase by deamination, thereby producing a partially protected 2'-O-derivatized uridine ribonucleoside which can be reacted at its 3'-hydroxyl group to produce a uridine RNA synthon.