Sodium borohydride → HCID 66608570, compound

Participants

Reaction Steps

The above Benzo[b]thiophen-2-yl (1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-indol-3-yl)ketone 92 (440 mg) was dissolved in tetrahydrofuran (6 ml) and ethanol (3 ml). To the solution was added sodium borohydride (137 mg), and the mixture was stirred at room temperature for 60 minutes. The reaction mixture was quenched with cold aqueous HCl solution (0.5 N), and extracted with ethyl acetate. The extract was washed successively with water, a saturated aqueous sodium hydrogen carbonate solution and brine, and dried over sodium sulfate. The solvent was evaporated under reduced pressure. The resultant residue was dissolved in dichloromethane (8 ml) and acetonitrile (4 ml), and the mixture was cooled to 0° C. under argon atmosphere. To the mixture were added triethylsilane (0.58 ml) and boron trifluoride.diethyl ether complex (0.46 ml). After 30 minutes, the mixture was basified with a saturated aqueous sodium hydrogen carbonate solution, and the organic layer was collected, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The resultant residue was dissolved in chloroform (20 ml), and to the mixture were added acetic anhydride (0.16 ml), triethylamine (0.2 ml), and 4-dimethylaminopyridine (15 mg), and the mixture was stirred at room temperature for 30 minutes. Then, the solution was washed successively with 10% aqueous hydrochloric acid solution, water, a saturated aqueous sodium hydrogen carbonate solution, and brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the resultant residue was purified by silica gel column chromatography (hexane:ethyl acetate=8:2-6:4) to give 1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-3-(benzo-[b]thiophen-2-ylmethyl)indole 93 (290 mg). APCI-Mass m/Z 611 (M+NH4).

Provenance & Evidence