Synthesis of 2′-(tert-butyloxycarbonyl)ribonucleosides A method for the introduction of the tert-butyloxycarbonyl-group (Boc) preferentially into the 2′-OH position of the ribonucleosides cytidine, uridine, adenosine and guanosine is described, resulting in derivatives especially applicable for ribonucleotide synthesis.