4-溴丁醛乙二缩醛

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of 4-hydroxymethylbenzoic acid (3.33 g, 21.9 mmol) in DMF (100 mL), was added potassium carbonate (5.67 g, 41.04 mmol) followed by 2-(3-bromopropyl)-1,3-dioxolane (3.0 g, 19.9 mmol). The resulting mixture was heated at 80° C. for 16 hours. The reaction mixture was diluted with ethyl acetate and washed sequentially with water and twice with brine. The organic phase was dried with anhydrous magnesium sulfate, and filtered, and the filtrate evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane to afford the title compound as a colourless oil (2.55 g, 48%). washed sequentially with water and twice with brine The organic phase was dried with anhydrous magnesium sulfate filtered the filtrate evaporated at reduced pressure The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane

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

实验步骤: At -70° C., 50 ml of a 1.2-molar solution of diisobutyl aluminum hydride in toluene is added dropwise gradually to a solution of 9.6 g of the ethyl ester of bromobutyric acid in 595 ml of toluene; the mixture is stirred for 15 minutes at -70° C. and then combined dropwise with 10 ml of isopropyl alcohol and 25 ml of water. The mixture is agitated for 2 hours at room temperature, filtered, the filtrate dried with magnesium sulfate and evaporated under vacuum at 25° C. The residue is dissolved in 500 ml of toluene, 10 ml of ethylene glycol and 100 mg of p-toluenesulfonic acid are added, and the mixture is refluxed for 6 hours with the use of a water trap. Subsequently the mixture is diluted with 500 ml of ether, shaken once with a 5% sodium bicarbonate solution and three times with water, the organic extract is dried with magnesium sulfate and concentrated under vacuum at 30° C. Distillation of the residue at 0.6 torr and 43°-45° C. yields 6.8 g of 2-(3-bromopropyl)-1,3-dioxolane as a colorless liquid. The mixture is agitated for 2 hours at room temperature filtered the filtrate dried with magnesium sulfate evaporated under vacuum at 25° C The residue is dissolved in 500 ml of toluene 10 ml of ethylene glycol and 100 mg of p-toluenesulfonic acid are added the mixture is refluxed for 6 hours with the use of a water trap Subsequently the mixture is diluted with 500 ml of ether shaken once with a 5% sodium bicarbonate solution and three times with water the organic extract is dried with magnesium sulfate concentrated under vacuum at 30° C Distillation of the residue at 0.6 torr and 43°-45° C.

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of 4-hydroxymethylbenzoic acid (3.33 g, 21.9 mmol) in DMF (100 mL), was added potassium carbonate (5.67 g, 41.04 mmol) followed by 2-(3-bromopropyl)-1,3-dioxolane (3.0 g, 19.9 mmol). The resulting mixture was heated at 80° C. for 16 hours. The reaction mixture was diluted with ethyl acetate and washed sequentially with water and twice with brine. The organic phase was dried with anhydrous magnesium sulfate, and filtered, and the filtrate evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane to afford the title compound as a colourless oil (2.55 g, 48%). washed sequentially with water and twice with brine The organic phase was dried with anhydrous magnesium sulfate filtered the filtrate evaporated at reduced pressure The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of 4-hydroxymethylbenzoic acid (3.33 g, 21.9 mmol) in DMF (100 mL), was added potassium carbonate (5.67 g, 41.04 mmol) followed by 2-(3-bromopropyl)-1,3-dioxolane (3.0 g, 19.9 mmol). The resulting mixture was heated at 80° C. for 16 hours. The reaction mixture was diluted with ethyl acetate and washed sequentially with water and twice with brine. The organic phase was dried with anhydrous magnesium sulfate, and filtered, and the filtrate evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane to afford the title compound as a colourless oil (2.55 g, 48%). washed sequentially with water and twice with brine The organic phase was dried with anhydrous magnesium sulfate filtered the filtrate evaporated at reduced pressure The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane

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

实验步骤: At -70° C., 50 ml of a 1.2-molar solution of diisobutyl aluminum hydride in toluene is added dropwise gradually to a solution of 9.6 g of the ethyl ester of bromobutyric acid in 595 ml of toluene; the mixture is stirred for 15 minutes at -70° C. and then combined dropwise with 10 ml of isopropyl alcohol and 25 ml of water. The mixture is agitated for 2 hours at room temperature, filtered, the filtrate dried with magnesium sulfate and evaporated under vacuum at 25° C. The residue is dissolved in 500 ml of toluene, 10 ml of ethylene glycol and 100 mg of p-toluenesulfonic acid are added, and the mixture is refluxed for 6 hours with the use of a water trap. Subsequently the mixture is diluted with 500 ml of ether, shaken once with a 5% sodium bicarbonate solution and three times with water, the organic extract is dried with magnesium sulfate and concentrated under vacuum at 30° C. Distillation of the residue at 0.6 torr and 43°-45° C. yields 6.8 g of 2-(3-bromopropyl)-1,3-dioxolane as a colorless liquid. The mixture is agitated for 2 hours at room temperature filtered the filtrate dried with magnesium sulfate evaporated under vacuum at 25° C The residue is dissolved in 500 ml of toluene 10 ml of ethylene glycol and 100 mg of p-toluenesulfonic acid are added the mixture is refluxed for 6 hours with the use of a water trap Subsequently the mixture is diluted with 500 ml of ether shaken once with a 5% sodium bicarbonate solution and three times with water the organic extract is dried with magnesium sulfate concentrated under vacuum at 30° C Distillation of the residue at 0.6 torr and 43°-45° C.

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirred solution of 4-hydroxymethylbenzoic acid (3.33 g, 21.9 mmol) in DMF (100 mL), was added potassium carbonate (5.67 g, 41.04 mmol) followed by 2-(3-bromopropyl)-1,3-dioxolane (3.0 g, 19.9 mmol). The resulting mixture was heated at 80° C. for 16 hours. The reaction mixture was diluted with ethyl acetate and washed sequentially with water and twice with brine. The organic phase was dried with anhydrous magnesium sulfate, and filtered, and the filtrate evaporated at reduced pressure. The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane to afford the title compound as a colourless oil (2.55 g, 48%). washed sequentially with water and twice with brine The organic phase was dried with anhydrous magnesium sulfate filtered the filtrate evaporated at reduced pressure The crude material was purified by silica gel chromatography eluting with 100% iso-hexane to 100% ethyl acetate in iso-hexane