To a stirred solution of acetic acid (2R,3R,4R,5S)-3,4,5-triacetoxy-6-[4-bromo-3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-phenyl]-tetrahydro-pyran-2-ylmethyl ester (10.0 g, 15.74 mmol) in toluene (100 mL) was added tricyclohexylphosphine (1.76 g, 6.29 mmol), a solution of potassium phosphate tribasic (13.3 g, 62.9 mmol) in water (15 mL), and cyclopropylboronic acid (4.06 g, 47.2 mmol). The reaction mixture was degassed for 45 min then palladium (II) acetate (529 mg, 2.3 mmol) was added. The reaction mixture was stirred at 90° C. overnight then cooled to room temperature and filtered through celite, and the celite was washed with ethyl acetate (200 mL). The organic layer of the filtrate was separated and washed with water (100 mL) followed by brine (100 mL), then dried over sodium sulfate and concentrated to give crude product which was further purified by column chromatography to furnish acetic acid (2R,3R,4R,5S)-3,4,5-triacetoxy-6-[4-cyclopropyl-3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-phenyl]-tetrahydro-pyran-2-ylmethyl ester (7.25 g, purity 98%) and this was recrystallized by absolute ethanol to give white solid (5.25 g, purity>99%).
