Coupling of alizarin blue (I) with the pyranosyl bromide (II) under Koenigs-Knorr conditions in the presence of HgO and HgBr2 afforded the target 5-talopyranoside derivative (III) along with minor amounts of the 5,6-bis-talopyranoside, which were separated by preparative thin layer chromatography. Deacetylation of (III) using NaOMe in MeOH-THF then gave the title compound.