Reaction SMILES: [C:1]([O:4][C@@H:5]1[C@@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@@H:8]([CH2:19][O:20][C:21](=[O:23])[CH3:22])[O:7][C@H:6]1[N:24]1[C:32]2[C:27](=[CH:28][CH:29]=[CH:30][CH:31]=2)[C:26]([C:33]([C:35]2[S:39][C:38]3[CH:40]=[CH:41][CH:42]=[CH:43][C:37]=3[CH:36]=2)=O)=[CH:25]1)(=[O:3])[CH3:2].[BH4-].[Na+]>O1CCCC1.C(O)C>[C:1]([O:4][C@@H:5]1[C@@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@@H:8]([CH2:19][O:20][C:21](=[O:23])[CH3:22])[O:7][C@H:6]1[N:24]1[C:32]2[C:27](=[CH:28][CH:29]=[CH:30][CH:31]=2)[C:26]([CH2:33][C:35]2[S:39][C:38]3[CH:40]=[CH:41][CH:42]=[CH:43][C:37]=3[CH:36]=2)=[CH:25]1)(=[O:3])[CH3:2]
Reactant: CC(=O)OC[C@H]1O[C@@H](n2cc(C(=O)c3cc4ccccc4s3)c3ccccc32)[C@H](OC(C)=O)[C@@H](OC(C)=O)[C@@H]1OC(C)=O
Agent: [BH4-]
Agent: [Na+]
Solvent: C1CCOC1
Solvent: CCO
Product: CC(=O)OC[C@H]1O[C@@H](n2cc(Cc3cc4ccccc4s3)c3ccccc32)[C@H](OC(C)=O)[C@@H](OC(C)=O)[C@@H]1OC(C)=O
Temperature: 25 °C
Reaction time: 1 h
Yield: 67.5 %

Procedure:
Benzo[b]thiophene-2-carboxylic acid (598 mg) was suspended in dichloromethane (10 ml). Added thereto were oxalyl chloride (0.39 ml) and N,N-dimethylformamide (one drop), and the mixture was stirred at room temperature overnight. The solvent was evaporated under reduced pressure to give a corresponding acid chloride, which was dissolved in dichloroethane (30 ml). To the solution was added 1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)indole 91 (1 g) obtained above, and the mixture was cooled to 0° C. Added gradually thereto was aluminum chloride (2.09 g), and subsequently, the mixture was stirred at the same temperature for 30 minutes. The reaction mixture was poured into ice-cold water, and the mixture was extracted with chloroform. The extract was washed successively with water, a saturated aqueous sodium hydrogen carbonate solution and brine, dried over sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1-5:4) to give Benzo[b]thiophen-2-yl (1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-indol-3-yl) ketone 92 (570 mg) as colorless crystals. APCI-Mass m/Z 608 (M+H). (3) The above Benzo[b]thiophen-2-yl (1-(2,3,4,6-tetra-Oacetyl-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). (4) The above 1-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl)-3-(benzo[b]thiophen-2-ylmethyl)indole 93 (336 mg) was treated in a manner similar to Example 106-(3) to give the desired 1-(β-D-glucopyranosyl)-3-(benzo[b]thiophen-2-ylmethyl)indole 94 (208 mg) as a colorless powder. APCI-Mass m/Z 443 (M+NH4).