This invention relates to a process for stereoselectively preparing a nucleoside of the following formula: ##STR00001## wherein R.sub.3, R.sub.4, and B are defined herein. The process includes reacting a furanose compound with a nucleobase in the presence of a halide salt. Also disclosed is another process for stereoselectively synthesizing an intermediate that can be used to make the starting compound in the first-mentioned process.