Solid-phase synthesis and on-column deprotection of RNA from 2'- (and 3'-) O-levulinated (Lv) ribonucleoside monomers

[reaction: see text] The solid-phase synthesis of oligoribonucleotides derived from ribonucleosides esterified at the 2'- (or 3'-) position with the levulinyl (Lv) group is described. The oligomers can be released from the solid support as 2'-O-Lv ester derivatives or fully deprotected while still attached to the solid support.