A potassium fluoride-promoted intramolecular cyclization reaction of 2-acetamido-2-deoxy-alpha-D-glucopyranosyl chloride took place smoothly, giving the corresponding 1,2-oxazoline derivative in good yield. Potassium fluoride behaves as a nucleophile for anomerization of the glycosyl chloride as well as an acid captor to scavenge the protonic acid liberated. This is an extremely practical method for preparation of sugar oxazoline derivatives with simple experimental procedures.