Chemical synthesis of RNA including 5-taurinomethyluridine and 5-taurinomethyl-2-thiouridine.

Recently, novel base-modified uridine derivatives, 5-taurinomethyluridine (tau m(5)U) and 5-taurinomethyl-2-thiouridine (tau m(5)s(2)U) have been discovered from mammalian mitochondrial tRNAs, and these modified ribonucleosides were found to exist at the first position of the anticodon. We herein report efficient reactions for the synthesis of RNA oligomers including these base-modified ribonucleosides.