To a solution of (2R,3R,4R,5S,65)-2-(Acetoxymethyl)-6-(4-chloro-3-(4-hydroxybenzyl)phenyl)tetrahydro-2H-pyran-3,4,5-triyl triacetate (500 mg, 0.91 mmol) in dry DMF (10 mL), was added (2-bromoethoxy)(tert-butyl)dimethylsilane (436 mg, 1.82 mmol) and cesium carbonate (890 mg, 2.73 mmol). The reaction was stirred at r.t. for 36 h. After completion of reaction, as confirmed by TLC, the reaction mixture was diluted with ethyl acetate (150 mL) and washed with water (3×10 mL). The organic layer was dried over anhydrous Na2SO4 and volatiles were evaporated in vacuo. The residue obtained was purified by column chromatography (silica gel, 4:6 Acetone:Pet. Ether) to afford title compound (392 mg, 60.85%) as white solid.
