Herein we wlsh to report the synthetic study on the precursor (10) of clemochi-nenoside-A(1), a new kind of macrocyclic glycoside, which was found in the roots of Clem-atics chinesis Osbeck (wei ling xian) that was used as Chinese herbal medicine for treatment of anthritis, arthralgia, headache and inflarnmation. The key steps were stereoselective gly-cosidation of 6 and selective mesylation of 9. Further studies are still going on,
