甲基-Β-D-吡喃葡萄糖苷半水合物

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: In the above Table I, it can be seen tht Sample A product composition gave a yield of 79.0% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, and only 10.81% of polyglycosides and dextrose. Sample D produced 77.12% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, while Sample G produced only 71.55% of the glucosides. At the same time, the percentages of polyglycosides and dextrose increased as the methanol:starch ratio decreased. The cost of removal of excess methanol must be balanced against the slightly increased yield of glucosides.

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Using a modification of the procedure as described: Tetrahedron, 1992, 48(47), 10249-10264. Methyl β-D-glucopyranoside (Biosynth International M-3592; 10.2 g, 50 mmol), benzaldehyde dimethylacetal (30 ml, 200 mmol) and 10-camphorsulfonic acid (116 mg, 0.5 mmol) in anhydrous acetonitrile (150 ml) was stirred at room temperature for 4 h. The reaction was checked by TLC to confirm complete conversion to the product (run in hexane: ethyl acetate, 1:2, visualised with ceric ammonium molybdate spray and heating. The reaction was then treated with triethylamine (1 ml) to neutralise the acid. The solution was filtered and the solid was washed with acetonitrile (20 ml). The mother solution was concentrated to about 60 ml, and it was again filtrated, and the filtrate washed with acetonitdrile (10 ml). The combined solid was dried in vacuum, to give 12.9 g (91%) of methyl 4,6-O-benzylidene-β-D-glucopyranoside. heating The solution was filtered the solid was washed with acetonitrile (20 ml) The mother solution was concentrated to about 60 ml, and it was again filtrated the filtrate washed with acetonitdrile (10 ml) The combined solid was dried in vacuum

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Using a modification of the procedure as described: Tetrahedron, 1992, 48(47), 10249-10264. Methyl β-D-glucopyranoside (Biosynth International M-3592; 10.2 g, 50 mmol), benzaldehyde dimethylacetal (30 ml, 200 mmol) and 10-camphorsulfonic acid (116 mg, 0.5 mmol) in anhydrous acetonitrile (150 ml) was stirred at room temperature for 4 h. The reaction was checked by TLC to confirm complete conversion to the product (run in hexane: ethyl acetate, 1:2, visualised with ceric ammonium molybdate spray and heating. The reaction was then treated with triethylamine (1 ml) to neutralise the acid. The solution was filtered and the solid was washed with acetonitrile (20 ml). The mother solution was concentrated to about 60 ml, and it was again filtrated, and the filtrate washed with acetonitdrile (10 ml). The combined solid was dried in vacuum, to give 12.9 g (91%) of methyl 4,6-O-benzylidene-β-D-glucopyranoside. heating The solution was filtered the solid was washed with acetonitrile (20 ml) The mother solution was concentrated to about 60 ml, and it was again filtrated the filtrate washed with acetonitdrile (10 ml) The combined solid was dried in vacuum

反应条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of methyl β-D-glucopyranoside (5 g, 25.7 mmol) in 51 mL of dry DMF was added at room temperature imidazole (5.46 g, 80.2 mmol) followed by tert-butyldiphenylsilyl chloride (11.3 mL, 43.4 mmol). The solution was heated to 50° C. for 24 hours and the DMF was removed under reduced pressure. The reaction mixture was diluted with 200 mL of ethyl acetate and washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL), and dried over magnesium sulfate. Concentration and flash chromatography (silica, 4% methanol in dichloromethane) provided pure target compound (9.82 g, 88%) as a white foam. the DMF was removed under reduced pressure The reaction mixture was diluted with 200 mL of ethyl acetate washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL) dried over magnesium sulfate Concentration and flash chromatography (silica, 4% methanol in dichloromethane)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: In the above Table I, it can be seen tht Sample A product composition gave a yield of 79.0% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, and only 10.81% of polyglycosides and dextrose. Sample D produced 77.12% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, while Sample G produced only 71.55% of the glucosides. At the same time, the percentages of polyglycosides and dextrose increased as the methanol:starch ratio decreased. The cost of removal of excess methanol must be balanced against the slightly increased yield of glucosides.

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: In the above Table I, it can be seen tht Sample A product composition gave a yield of 79.0% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, and only 10.81% of polyglycosides and dextrose. Sample D produced 77.12% methyl-alpha-D-glucopyranoside and methyl-beta-D-glucopyranoside, while Sample G produced only 71.55% of the glucosides. At the same time, the percentages of polyglycosides and dextrose increased as the methanol:starch ratio decreased. The cost of removal of excess methanol must be balanced against the slightly increased yield of glucosides.

反应条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of methyl β-D-glucopyranoside (5 g, 25.7 mmol) in 51 mL of dry DMF was added at room temperature imidazole (5.46 g, 80.2 mmol) followed by tert-butyldiphenyl-silyl chloride (11.3 mL, 43.4 mmol). The solution was heated to 50° C. for 24 hours and the DMF was removed under reduced pressure. The reaction mixture was diluted with 200 mL of ethyl acetate and washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL), and dried over magnesium sulfate. Concentration and flash chromatography (silica, 4% methanol in dichloromethane) provided pure target compound (9.82 g, 88%) as a white foam. the DMF was removed under reduced pressure The reaction mixture was diluted with 200 mL of ethyl acetate washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL) dried over magnesium sulfate Concentration and flash chromatography (silica, 4% methanol in dichloromethane)

反应条件: temp:115.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A general procedure according to S. Koto et al. (Bull. Chem. Soc. Japan, (1976), 49:2939-40) was followed. A suspension of methyl-α-D-glucopyranoside (Aldrich, 5.02 g, 0.0259 mol), sodium hydride (Aldrich, 4.31 g, 0.1796 mol) and benzyl chloride (Aldrich, 125 ml, 25:1 (v/w) vs carbohydrate) was stirred vigorously and heated to a bath temperature of 115° C. whereupon the gray reaction mixture thickened and an exotherm occurred. The reaction mixture reached 135° C. and turned into a thin, yellowish slurry. The reaction was allowed to stir at this temperature for 1 h. The insoluble material was removed by filtration and the solution concentrated in vacuo. Flash chromatography on silica gel (E. M. Science, 230-400 mesh) using methylene chloride as eluant gave the product (Rf value: 0.63) as an oil (7.45 g, 52%). 1H NMR data (CDCl3): δ7.27 (m, 20H, aromatic H on benzyl group), 3.45 (s, 3H, --OCH3 ). reached 135° C. to stir at this temperature for 1 h The insoluble material was removed by filtration the solution concentrated in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Methyl-D-glucopyranoside (19.8 g, 0.10 mol, a 1:1 mixture of methyl α-(D)-glucopyranoside and methyl β-(D)-glucopyranoside, both Sigma Chemicals) was esterified with dodecanoic acid (31 g, 0.15 mol) by the procedure described in Example 1, using 3 g of an immobilized lipase (derived from Candida antarctica). The reaction was complete in 24 hours (HPLC showed>90% conversion) and the enzyme was removed by filtration. Purification by chromatography provided the title compound in a yield of 79% (30 g) as a crystalline powder, m,p. 70°-72° C. (HPLC showed>90% conversion) and the enzyme was removed by filtration Purification by chromatography

反应条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of methyl β-D-glucopyranoside (5 g, 25.7 mmol) in 51 mL of dry DMF was added at room temperature imidazole (5.46 g, 80.2 mmol) followed by tert-butyldiphenyl-silyl chloride (11.3 mL, 43.4 mmol). The solution was heated to 50° C. for 24 hours and the DMF was removed under reduced pressure. The reaction mixture was diluted with 200 mL of ethyl acetate and washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL), and dried over magnesium sulfate. Concentration and flash chromatography (silica, 4% methanol in dichloromethane) provided pure target compound (9.82 g, 88%) as a white foam. the DMF was removed under reduced pressure The reaction mixture was diluted with 200 mL of ethyl acetate washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL) dried over magnesium sulfate Concentration and flash chromatography (silica, 4% methanol in dichloromethane)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Using a modification of the procedure as described: Tetrahedron, 1992, 48(47), 10249-10264. Methyl β-D-glucopyranoside (Biosynth International M-3592; 10.2 g, 50 mmol), benzaldehyde dimethylacetal (30 ml, 200 mmol) and 10-camphorsulfonic acid (116 mg, 0.5 mmol) in anhydrous acetonitrile (150 ml) was stirred at room temperature for 4 h. The reaction was checked by TLC to confirm complete conversion to the product (run in hexane: ethyl acetate, 1:2, visualised with ceric ammonium molybdate spray and heating. The reaction was then treated with triethylamine (1 ml) to neutralise the acid. The solution was filtered and the solid was washed with acetonitrile (20 ml). The mother solution was concentrated to about 60 ml, and it was again filtrated, and the filtrate washed with acetonitdrile (10 ml). The combined solid was dried in vacuum, to give 12.9 g (91%) of methyl 4,6-O-benzylidene-β-D-glucopyranoside. heating The solution was filtered the solid was washed with acetonitrile (20 ml) The mother solution was concentrated to about 60 ml, and it was again filtrated the filtrate washed with acetonitdrile (10 ml) The combined solid was dried in vacuum

反应条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of methyl β-D-glucopyranoside (5 g, 25.7 mmol) in 51 mL of dry DMF was added at room temperature imidazole (5.46 g, 80.2 mmol) followed by tert-butyldiphenylsilyl chloride (11.3 mL, 43.4 mmol). The solution was heated to 50° C. for 24 hours and the DMF was removed under reduced pressure. The reaction mixture was diluted with 200 mL of ethyl acetate and washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL), and dried over magnesium sulfate. Concentration and flash chromatography (silica, 4% methanol in dichloromethane) provided pure target compound (9.82 g, 88%) as a white foam. the DMF was removed under reduced pressure The reaction mixture was diluted with 200 mL of ethyl acetate washed with H2O (1×100 mL), saturated aqueous NaCl (1×100 mL) dried over magnesium sulfate Concentration and flash chromatography (silica, 4% methanol in dichloromethane)