1,4-Dibromobenzene → 2,3,4,6-tetra-O-benzyl-1-C-[2-(benzyloxy)-5-[(4-bromophenyl)(hydroxy)methyl]-4-methylphenyl]-D-glucopyranose

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Reaction Steps

To a tetrahydrofuran solution (80 mL) of 1,4-dibromobenzene (6.20 g, 26.1 mmol) was added dropwise under nitrogen atmosphere at −78° C. a 2.67 M n-butyllithium solution in hexane (10.5 mL, 26.1 mmol), and the mixture was stirred for 15 minutes at the same temperature. Then a tetrahydrofuran solution (20 mL) of 2,3,4,6-tetra-O-benzyl-1-C-[2-(benzyloxy)-5-formyl-4-methylphenyl]-D-glucopyranose (10.0 g, 13.0 mmol) was added dropwise, and the mixture was stirred for 30 minutes at the same temperature. To the reaction solution was added a saturated aqueous solution of ammonium chloride, and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with brine, and dried with anhydrous magnesium sulfate. The drying agent was filtered off, and the solvent was evaporated under reduced pressure. Thus obtained residue was purified with silica gel column chromatography (hexane:ethyl acetate=2:1). In addition, the residue was further purified with NH type silica gel column chromatography (hexane:ethyl acetate=1:1) to obtain the yellow oily title compound (5.50 g, 46%) as a diastereomeric mixture.

Provenance & Evidence