ethyl 5-bromo-3,3-dimethylpentanoate

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzenesulphonamide (9.6 g, 61.1 mmol) was added to a stirred solution of sodium methoxide (1.6 g, 29.6 mmol) in methanol (100 ml). The clear solution was evaporated to dryness, then dimethyl formamide (100 ml) and ethyl 5-bromo-3,3-dimethyl-pentanoate (7.0 g, 32.8 mmol) were added and the mixture was heated for eight hours at 70° C. The solution was then poured into water (600 ml), the mixture was extracted with ether and the ether phase, after being dried over sodium sulphate, was evaporated. Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved. After filtration, the solution was evaporated and the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2). Yield: 4.6 g (50% of theory), oily substance, nD20 =1.5083. The clear solution was evaporated to dryness the mixture was extracted with ether the ether phase, after being dried over sodium sulphate was evaporated Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved After filtration the solution was evaporated the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 50 ml. dimethyl sulphoxide and 42.2 mmol sodium hydride is maintained at 80° C. for 45 minutes. It is then cooled to ambient temperature, 3.3 g. (42,2 mmol) 2-mercaptoethanol and then 10.0 g. (42,2 mmol) ethyl 5-bromo-3,3-dimethylpentanoate are added thereto and the reaction mixture is stirred for 3 hours at ambient temperature. It is then poured into water and extracted with diethyl ether. The ethereal phase is dried with anhydrous sodium sulphate and then evaporated. After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g. (70% of theory) of the desired product in the form of a colourless oil. A mixture of 50 ml extracted with diethyl ether The ethereal phase is dried with anhydrous sodium sulphate evaporated After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 50 ml. dimethyl sulphoxide and 42.2 mmol sodium hydride is maintained at 80° C. for 45 minutes. It is then cooled to ambient temperature, 3.3 g. (42,2 mmol) 2-mercaptoethanol and then 10.0 g. (42,2 mmol) ethyl 5-bromo-3,3-dimethylpentanoate are added thereto and the reaction mixture is stirred for 3 hours at ambient temperature. It is then poured into water and extracted with diethyl ether. The ethereal phase is dried with anhydrous sodium sulphate and then evaporated. After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g. (70% of theory) of the desired product in the form of a colourless oil. A mixture of 50 ml extracted with diethyl ether The ethereal phase is dried with anhydrous sodium sulphate evaporated After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzenesulphonamide (9.6 g, 61.1 mmol) was added to a stirred solution of sodium methoxide (1.6 g, 29.6 mmol) in methanol (100 ml). The clear solution was evaporated to dryness, then dimethyl formamide (100 ml) and ethyl 5-bromo-3,3-dimethyl-pentanoate (7.0 g, 32.8 mmol) were added and the mixture was heated for eight hours at 70° C. The solution was then poured into water (600 ml), the mixture was extracted with ether and the ether phase, after being dried over sodium sulphate, was evaporated. Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved. After filtration, the solution was evaporated and the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2). Yield: 4.6 g (50% of theory), oily substance, nD20 =1.5083. The clear solution was evaporated to dryness the mixture was extracted with ether the ether phase, after being dried over sodium sulphate was evaporated Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved After filtration the solution was evaporated the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2)

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzenesulphonamide (9.6 g, 61.1 mmol) was added to a stirred solution of sodium methoxide (1.6 g, 29.6 mmol) in methanol (100 ml). The clear solution was evaporated to dryness, then dimethyl formamide (100 ml) and ethyl 5-bromo-3,3-dimethyl-pentanoate (7.0 g, 32.8 mmol) were added and the mixture was heated for eight hours at 70° C. The solution was then poured into water (600 ml), the mixture was extracted with ether and the ether phase, after being dried over sodium sulphate, was evaporated. Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved. After filtration, the solution was evaporated and the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2). Yield: 4.6 g (50% of theory), oily substance, nD20 =1.5083. The clear solution was evaporated to dryness the mixture was extracted with ether the ether phase, after being dried over sodium sulphate was evaporated Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved After filtration the solution was evaporated the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 50 ml. dimethyl sulphoxide and 42.2 mmol sodium hydride is maintained at 80° C. for 45 minutes. It is then cooled to ambient temperature, 3.3 g. (42,2 mmol) 2-mercaptoethanol and then 10.0 g. (42,2 mmol) ethyl 5-bromo-3,3-dimethylpentanoate are added thereto and the reaction mixture is stirred for 3 hours at ambient temperature. It is then poured into water and extracted with diethyl ether. The ethereal phase is dried with anhydrous sodium sulphate and then evaporated. After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g. (70% of theory) of the desired product in the form of a colourless oil. A mixture of 50 ml extracted with diethyl ether The ethereal phase is dried with anhydrous sodium sulphate evaporated After chromatography of the residue on silica gel with a mixture of equal parts by volume of diethyl ether and cyclohexane, there are obtained 6.8 g

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzenesulphonamide (9.6 g, 61.1 mmol) was added to a stirred solution of sodium methoxide (1.6 g, 29.6 mmol) in methanol (100 ml). The clear solution was evaporated to dryness, then dimethyl formamide (100 ml) and ethyl 5-bromo-3,3-dimethyl-pentanoate (7.0 g, 32.8 mmol) were added and the mixture was heated for eight hours at 70° C. The solution was then poured into water (600 ml), the mixture was extracted with ether and the ether phase, after being dried over sodium sulphate, was evaporated. Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved. After filtration, the solution was evaporated and the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2). Yield: 4.6 g (50% of theory), oily substance, nD20 =1.5083. The clear solution was evaporated to dryness the mixture was extracted with ether the ether phase, after being dried over sodium sulphate was evaporated Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved After filtration the solution was evaporated the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2)