The general procedure for the synthesis of 2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-7-(((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-4H-benzopyran-4-one was carried out in the following general steps, using the compound (CAS: 1313191-79-5) as starting material: compound 8 (50 mg, 0.06 mmol) was suspended in a mixed solvent of ethanol (EtOH, 20 mL) and tetrahydrofuran (THF, 20 mL), palladium hydroxide (30%, 30 mg) was added as a catalyst under hydrogen atmosphere, and the reaction lasted for 12 hours. Upon completion of the reaction, the reaction mixture was filtered through diatomaceous earth and the filter cake was washed with ethanol (EtOH, 30 mL). After the solvent was removed by evaporation, the resulting residue was purified by chromatography on a C18 reversed-phase column with the eluent being a solvent mixture of methanol (MeOH) and water (H2O) (30:70, v/v). The final target product was obtained as 20 mg in 72% yield.
