Patent ID: 7485716

Claim:
A process comprising: reacting a furan compound of the following formula: in which each of R 1 and R 2 independently is a hydroxy protecting group, or R 1 and R 2 , together, are C 1-3 alkylene; each of R 3 and R 4 independently is H, halo, alkoxy, alkyl, or aryl, and L is a leaving group; with a compound of the following formula: in which R 5 is H, alkyl, or aryl; R 6 is H, alkyl, alkenyl, halo, or aryl; X is N or C—R′, R′ being H, alkyl, alkenyl, halo, or aryl; Y is an amino protecting group; and Z is a hydroxy protecting group; in the presence of a halide salt at 110-200° C. to stereoselectively form a β-nucleoside of the following formula: in which R 1 , R 2 , R 3 , and R 4 are defined above and B is in which X, Y, R 5 , and R 6 are defined above.