By use of a palladium catalyzed decarboxylation reaction, the allyl group has been introduced at the 2' position of uridine and adenosine suitably protected by tetraisopropyldisiloxanyl group and the benzoyl group. E.g., uridine I (R = CH2CH:CH2) was prepared from I (R = H) via I (R = CO2CH2CH:CH2).

Key words: PYRIDINE P, CATALYSIS, URIDINE, TRIPHENYLPHOSPHINE, ADENOSINE, PALLADIUM COMPLEX, DECARBOXYLATION, ALLYLATION