2,2-Dimethylbutanoic acid methyl ester

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Dimethyl methylphosphonate (9.3 g, 0.075 mol) was dissolved in anhydrous THF (80 ml) under argon atmosphere. To the solution stirred at -78° C. was added dropwise n-butyl lithium (1.61N, 47 ml, 0.075 mol) over 30 minutes, and then a solution of 2,2-dimethylbutanoic acid methyl ester (3.9 g, 0.03 mol) in anhydrous THF (10 ml) was also added dropwise over 30 minutes. The reaction mixture was warmed to room temperature and stirred for 30 minutes. Under ice cooling, acetic acid (4.5 ml) and water (10 ml) were added to the mixture. After concentration, water (20 ml) was added to the residue, and the mixture was then extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate, and concentrated. Distillation of the residue gave dimethyl 3,3-dimethyl-2-oxo-pentylphosphonate (3.36 g, 0.015 mol, yield: 50%, b.p.=115-117/0.5 mmHg). The structure was identified by the following data. The reaction mixture was warmed to room temperature stirred for 30 minutes After concentration, water (20 ml) was added to the residue the mixture was then extracted with ethyl acetate (50 ml×2) The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1) dried over anhydrous sodium sulfate concentrated Distillation of the residue

反应条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Dimethyl methylphosphonate (9.3 g, 0.075 mol) was dissolved in anhydrous THF (80 ml) under argon atmosphere. To the solution stirred at -78° C. was added dropwise n-butyl lithium (1.61N, 47 ml, 0.075 mol) over 30 minutes, and then a solution of 2,2-dimethylbutanoic acid methyl ester (3.9 g, 0.03 mol) in anhydrous THF (10 ml) was also added dropwise over 30 minutes. The reaction mixture was warmed to room temperature and stirred for 30 minutes. Under ice cooling, acetic acid (4.5 ml) and water (10 ml) were added to the mixture. After concentration, water (20 ml) was added to the residue, and the mixture was then extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate, and concentrated. Distillation of the residue gave dimethyl 3,3-dimethyl-2-oxo-pentylphosphonate (3.36 g, 0.015 mol, yield: 50%, b.p.=115-117/0.5 mmHg). The structure was identified by the following data. The reaction mixture was warmed to room temperature stirred for 30 minutes After concentration, water (20 ml) was added to the residue the mixture was then extracted with ethyl acetate (50 ml×2) The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1) dried over anhydrous sodium sulfate concentrated Distillation of the residue

反应条件: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Anhydrous diisopropylamine (11.5 g, 0.114 mol) was dissolved in anhydrous THF (50 ml) under argon atmosphere. To the mixture stirred at -20° C. was added dropwise n-butyl lithium (1.62N, 70 ml, 0.114 mol) over 30 minutes, then a solution of isobutyric acid (5.0 g, 0.057 mol) in anhydrous THF (10 ml) was added dropwise over 30 minutes, and further a solution of ethyl bromide (6.2 g, 0.057 mol) in anhydrous THF (10 ml) was also added dropwise over one hour. Aqueous hydrogen chloride (6N) was added to adjust pH to 2 near 0° C. The reaction mixture was extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate and concentrated. The residue was dissolved in ether (30 ml) and an excess of an ethereal solution of diazomethane was added. Distillation under an atmospheric pressure gave 2,2-dimethyl-butanoic acid methyl ester (5.3 g, 0.046 mol, yield 80.2%, b.p.=115°-120° C.) as a colorless clear liquid. The structure was identified by the following data. to adjust pH to 2 near 0° C The reaction mixture was extracted with ethyl acetate (50 ml×2) The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1) dried over anhydrous sodium sulfate concentrated The residue was dissolved in ether (30 ml) an excess of an ethereal solution of diazomethane was added Distillation under an atmospheric pressure

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Dimethyl methylphosphonate (9.3 g, 0.075 mol) was dissolved in anhydrous THF (80 ml) under argon atmosphere. To the solution stirred at -78° C. was added dropwise n-butyl lithium (1.61N, 47 ml, 0.075 mol) over 30 minutes, and then a solution of 2,2-dimethylbutanoic acid methyl ester (3.9 g, 0.03 mol) in anhydrous THF (10 ml) was also added dropwise over 30 minutes. The reaction mixture was warmed to room temperature and stirred for 30 minutes. Under ice cooling, acetic acid (4.5 ml) and water (10 ml) were added to the mixture. After concentration, water (20 ml) was added to the residue, and the mixture was then extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate, and concentrated. Distillation of the residue gave dimethyl 3,3-dimethyl-2-oxo-pentylphosphonate (3.36 g, 0.015 mol, yield: 50%, b.p.=115-117/0.5 mmHg). The structure was identified by the following data. The reaction mixture was warmed to room temperature stirred for 30 minutes After concentration, water (20 ml) was added to the residue the mixture was then extracted with ethyl acetate (50 ml×2) The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1) dried over anhydrous sodium sulfate concentrated Distillation of the residue

反应条件: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Anhydrous diisopropylamine (11.5 g, 0.114 mol) was dissolved in anhydrous THF (50 ml) under argon atmosphere. To the mixture stirred at -20° C. was added dropwise n-butyl lithium (1.62N, 70 ml, 0.114 mol) over 30 minutes, then a solution of isobutyric acid (5.0 g, 0.057 mol) in anhydrous THF (10 ml) was added dropwise over 30 minutes, and further a solution of ethyl bromide (6.2 g, 0.057 mol) in anhydrous THF (10 ml) was also added dropwise over one hour. Aqueous hydrogen chloride (6N) was added to adjust pH to 2 near 0° C. The reaction mixture was extracted with ethyl acetate (50 ml×2). The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1), dried over anhydrous sodium sulfate and concentrated. The residue was dissolved in ether (30 ml) and an excess of an ethereal solution of diazomethane was added. Distillation under an atmospheric pressure gave 2,2-dimethyl-butanoic acid methyl ester (5.3 g, 0.046 mol, yield 80.2%, b.p.=115°-120° C.) as a colorless clear liquid. The structure was identified by the following data. to adjust pH to 2 near 0° C The reaction mixture was extracted with ethyl acetate (50 ml×2) The ethyl acetate layers were washed with water (20 ml×1) and with brine (20 ml×1) dried over anhydrous sodium sulfate concentrated The residue was dissolved in ether (30 ml) an excess of an ethereal solution of diazomethane was added Distillation under an atmospheric pressure