[(2S,4R)-4,5-diacetyloxyoxolan-2-基]苯甲酸甲酯

反应条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (4.42 g, 24.0 mmol) in ACN (20 mL) was added BSA (14.8 mL, 60.0 mmol). The resulting reaction mixture was then stirred at 70° C. under argon for 0.5 hr to form a clear solution. After the solution was cooled to room temperature, [(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]methyl benzoate (CAS #: 4613-71-2, Cat.#: MD04725, commercially available from Carbosynth Limited, 6.45 g, 20.0 mmol) and TMSOTf (5.5 mL, 30.0 mmol) were added in sequence. After being heated with stirring at 70° C. for 14 hours, the solvent was removed in vacuo. The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL). The organic layer was separated and the aqueous phase was extracted with EtOAc (100 mL) twice. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel to afford 5.7 g of [(2S,4R,5R)-4-acetoxy-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)tetrahydrofuran-2-yl]methyl benzoate (compound 38a) as a light yellow solid. was added BSA (14.8 mL, 60.0 mmol) The resulting reaction mixture to form a clear solution After the solution was cooled to room temperature After being heated with stirring at 70° C. for 14 hours the solvent was removed in vacuo The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL) The organic layer was separated the aqueous phase was extracted with EtOAc (100 mL) twice The combined organic layers were washed with brine dried over Na2SO4 concentrated in vacuo The residue was purified by column chromatography on silica gel

反应条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (4.42 g, 24.0 mmol) in ACN (20 mL) was added BSA (14.8 mL, 60.0 mmol). The resulting reaction mixture was then stirred at 70° C. under argon for 0.5 hr to form a clear solution. After the solution was cooled to room temperature, [(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]methyl benzoate (CAS #: 4613-71-2, Cat.#: MD04725, commercially available from Carbosynth Limited, 6.45 g, 20.0 mmol) and TMSOTf (5.5 mL, 30.0 mmol) were added in sequence. After being heated with stirring at 70° C. for 14 hours, the solvent was removed in vacuo. The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL). The organic layer was separated and the aqueous phase was extracted with EtOAc (100 mL) twice. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel to afford 5.7 g of [(2S,4R,5R)-4-acetoxy-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)tetrahydrofuran-2-yl]methyl benzoate (compound 38a) as a light yellow solid. was added BSA (14.8 mL, 60.0 mmol) The resulting reaction mixture to form a clear solution After the solution was cooled to room temperature After being heated with stirring at 70° C. for 14 hours the solvent was removed in vacuo The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL) The organic layer was separated the aqueous phase was extracted with EtOAc (100 mL) twice The combined organic layers were washed with brine dried over Na2SO4 concentrated in vacuo The residue was purified by column chromatography on silica gel

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

实验步骤: A catalytic amount of ammonium sulfate was added to a mixture of 6-chloropurine (0.56 grams, 3.62 mmol) and hexamethyldisilazane (15 mL), and the mixture was refluxed for 3 hours. The solvent was evaporated under reduced pressure, and the residue was co-evaporated with dry toluene (3×10 mL). The white solid residue was dissolved in dry methylene chloride (40 mL) and 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-ribofuranose, (1.00 g, 3.10 mmol) was added. After 10 minutes of stirring, trimethylsilyl triflate (0.8 mL) was added, and the solution stirred at room temperature for an additional 3 hours. A solution of cold, saturated sodium bicarbonate was added. After 5 minutes stirring, the organic layer was separated and the aqueous solution extracted with methylene chloride (2×30 mL). The organic layers were combined and dried over sodium sulfate, to give (5S,2R,3R)-2-(6-chloropurin-9-yl)-5-(phenylcarbonyloxymethyl)oxolan-3-yl acetate, which was purified by crystallization from methanol. The mother liquor was chromatographed on a Chromatotron, to provide additional product. the mixture was refluxed for 3 hours The solvent was evaporated under reduced pressure The white solid residue was dissolved in dry methylene chloride (40 mL) the solution stirred at room temperature for an additional 3 hours After 5 minutes stirring the organic layer was separated the aqueous solution extracted with methylene chloride (2×30 mL) dried over sodium sulfate

反应条件: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a suspension of 5-amino-3,6-dihydrothiazolo[4,5-d]pyrimidine-2,7-dione (4.42 g, 24.0 mmol) in ACN (20 mL) was added BSA (14.8 mL, 60.0 mmol). The resulting reaction mixture was then stirred at 70° C. under argon for 0.5 hr to form a clear solution. After the solution was cooled to room temperature, [(2S,4R)-4,5-diacetoxytetrahydrofuran-2-yl]methyl benzoate (CAS #: 4613-71-2, Cat.#: MD04725, commercially available from Carbosynth Limited, 6.45 g, 20.0 mmol) and TMSOTf (5.5 mL, 30.0 mmol) were added in sequence. After being heated with stirring at 70° C. for 14 hours, the solvent was removed in vacuo. The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL). The organic layer was separated and the aqueous phase was extracted with EtOAc (100 mL) twice. The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel to afford 5.7 g of [(2S,4R,5R)-4-acetoxy-5-(5-amino-2,7-dioxo-6H-thiazolo[4,5-d]pyrimidin-3-yl)tetrahydrofuran-2-yl]methyl benzoate (compound 38a) as a light yellow solid. was added BSA (14.8 mL, 60.0 mmol) The resulting reaction mixture to form a clear solution After the solution was cooled to room temperature After being heated with stirring at 70° C. for 14 hours the solvent was removed in vacuo The residue was partitioned between EtOAc and saturated NaHCO3 solution (30 mL) The organic layer was separated the aqueous phase was extracted with EtOAc (100 mL) twice The combined organic layers were washed with brine dried over Na2SO4 concentrated in vacuo The residue was purified by column chromatography on silica gel