alpha-D-Glucopyranosyl bromide, tetraacetate → 5-isopropyl-4-(2-benzyloxybenzyl)-3-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyloxy)-1H-pyrazole

Participants

Reaction Steps

To a suspension of 4-(2-benzyloxybenzyl)-5-isopropyl-1,2-dihydropyrazol-3-one (114 mg) and acetobromo-α-D-glucose (173 mg) in acetonitrile (2 mL) was added silver carbonate (127 mg), and the mixture was stirred under shading the light at room temperature for 3 days. The reaction mixture was purified by column chromatography on aminopropyl silica gel (eluent: ethyl acetate/hexane=1/1) to give 5-isopropyl-4-(2-benzyloxybenzyl)-3-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-1H-pyrazole. To a solution of 5-isopropyl-4-(2-benzyloxybenzyl)-3-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxy)-1H-pyrazole in tetrahydrofuran (1 mL) and methanol (0.5 mL) was added sodium methoxide (28% methanol solution, 50 μL), and the mixture was stirred at room temperature for 1 hour. The reaction mixture was concentrated under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: dichloromethane/methanol=10/1-5/1) to give the title compound (22 mg).

Provenance & Evidence