Asynthesis of b-nucleosides

A process of preparing a β-nucleoside compound formula (I):

• wherein
• each of R1 and R2, independently, is H, alkyl, aryl, aralkyl, alkyldiarylsilyl, trialkylsilyl, triarylsilyl, RC(O)—, RR′NC(O)—, ROC(O)—, RC(S)—, RR′NC(S)—, or ROC(S)—;
• each of R and R′, independently, being H, alkyl, aryl, cycloalkyl, heterocycloalkyl, or heteroaryl;
• each of R3 and R4, independently, is H or fluoro;
• and
• B is
• in which R5 is H, alkyl, or aryl;
• R6 is H, alkyl, alkenyl, halo, or aryl;
• X is N or C—R″, R″ being H, alkyl, alkenyl, halo, amino, or aryl;
• and Y is an amino protecting group;
• the process comprising reacting, in the presence of an oxidizing agent, a tetrahydrofuran compound of formula (II):
• wherein R1, R2, R3, and R4 are as defined above and L is chloro, bromo, or iodio, with a nucleobase derivative of the following formula:
• wherein R5, R6, X, and Y are as defined above and Z is a hydroxyl protecting group;
• in which the oxidizing agent is Br2, H2O2, O2, Cl2, O3, F2, 3-chloroperbezoic acid, azobisisobutyronitrile, 2,2,6,6-tetramethylpiperidine 1-oxyl, or a salt including an ion selected from the group consisting of Fe3+, Ce4+, Au3+, Co3+, NO3−, MnO4−, Cr2O72−, HSO5−, and S2O82−.