Efficient Synthesis of D-(5-13C)Ribose from D-Ribose and Its Conversion into (5′-13C)Nucleosides.

An approach to the synthesis of [5-13C]ribose (6) was achieved by a sequence reaction as follows: periodate oxidation of 2,3-di-O-benzyl-d-ribose dibenzyl acetal (2), which was derived from d-ribose (1) in 70% overall yield in 8 steps, followed by the introduction of 13C into the 5-position of d-ribose by Wittig reaction using Ph3P13CH3I - BuLi, highly diastereoselective hydroxylation with OsO4, and then debenzylation. Compound 6 with the necessary protecting groups and a leaving group was derived into [5′-13C]ribonucleoside derivatives by the coupling reaction with persilylated nucleobases.