(R)-3,7-dimethyl-1-octanol

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

实验步骤: 5.65 g (31.8 mmol) of N-bromosuccinimide are added portionwise while stirring to a solution of 5 g (31.6 mmol) of (R)-3,7-dimethyl-1-octanol and 9.05 g (34.5 mmol) of triphenylphosphine in 20 ml of methylene chloride. The temperature is held below 25° by occasional cooling of the reaction vessel. After 30-minutes stirring at room temperature, the solvent is removed on the rotary evaporator. The residue is washed out several times with n-hexane, then filtered and again rinsed with n-hexane. The combined n-hexane phases are concentrated on the rotary evaporator and the crude product is chromatographed on 200 g of silicagel with n-hexane. Distillation in the bulb-tube at 105°/15 Torr gives 6.1 g (87%) of (R)-1-bromo-3,7-dimethyloctane; [α]D20 =-5.0 (c=0.82, CHCl3). is held below 25° by occasional cooling of the reaction vessel the solvent is removed on the rotary evaporator The residue is washed out several times with n-hexane filtered again rinsed with n-hexane The combined n-hexane phases are concentrated on the rotary evaporator the crude product is chromatographed on 200 g of silicagel with n-hexane Distillation in the bulb-tube at 105°/15 Torr

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

实验步骤: A solution of 6.5 g (41 mmol) of (R)-3,7-dimethyl-1-octanol and 7.8 g (41 mmol) of p-toluenesulphonyl chloride in 50 ml of absolute chloroform is treated at 0° with 7.9 g (0.1 mol) of absolute pyridine. The mixture is subsequently stirred at 4° for 20 hours. For the working-up the mixture is poured on to 500 g of ice and extracted three times with chloroform. The combined organic phases are washed first with cold 1-N hydrochloric acid, then with saturated aqueous sodium bicarbonate solution and subsequently with saturated aqueous common salt solution. After drying over potassium carbonate and removal of the solvent under reduced pressure, the crude product is chromatographed on 300 g of silicagel with benzene. There are obtained 11.4 g (89%) of (R)-3,7-dimethyl-1-octanol p-toluenesulphonate; [α]D20 =+2.0 (c=4.0, benzene). extracted three times with chloroform The combined organic phases are washed first with cold 1-N hydrochloric acid After drying over potassium carbonate and removal of the solvent under reduced pressure the crude product is chromatographed on 300 g of silicagel with benzene

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

实验步骤: 5.65 g (31.8 mmol) of N-bromosuccinimide are added portionwise while stirring to a solution of 5 g (31.6 mmol) of (R)-3,7-dimethyl-1-octanol and 9.05 g (34.5 mmol) of triphenylphosphine in 20 ml of methylene chloride. The temperature is held below 25° by occasional cooling of the reaction vessel. After 30-minutes stirring at room temperature, the solvent is removed on the rotary evaporator. The residue is washed out several times with n-hexane, then filtered and again rinsed with n-hexane. The combined n-hexane phases are concentrated on the rotary evaporator and the crude product is chromatographed on 200 g of silicagel with n-hexane. Distillation in the bulb-tube at 105°/15 Torr gives 6.1 g (87%) of (R)-1-bromo-3,7-dimethyloctane; [α]D20 = -5.0 (c = 0.82, CHCl3). is held below 25° by occasional cooling of the reaction vessel the solvent is removed on the rotary evaporator The residue is washed out several times with n-hexane filtered again rinsed with n-hexane The combined n-hexane phases are concentrated on the rotary evaporator the crude product is chromatographed on 200 g of silicagel with n-hexane Distillation in the bulb-tube at 105°/15 Torr

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

实验步骤: A solution of 6.5 g (41 mmol) of (R)-3,7-dimethyl-1-octanol and 7.8 g (41 mmol) of p-toluenesulphonyl chloride in 50 ml of absolute chloroform is treated at 0° with 7.9 g (0.1 mol) of absolute pyridine. The mixture is subsequently stirred at 4° for 20 hours. For the working-up the mixture is poured on to 500 g of ice and extracted three times with chloroform. The combined organic phases are washed first with cold 1-N hydrochloric acid, then with saturated aqueous sodium bicarbonate solution and subsequently with saturated aqueous common salt solution. After drying over potassium carbonate and removal of the solvent under reduced pressure, the crude product is chromatographed on 300 g of silicagel with benzene. There are obtained 11.4 g (89%) of (R)-3,7-dimethyl-1-octanol p-toluenesulphonate; [α]D20 = +2.0 (c = 4.0, benzene). extracted three times with chloroform The combined organic phases are washed first with cold 1-N hydrochloric acid After drying over potassium carbonate and removal of the solvent under reduced pressure the crude product is chromatographed on 300 g of silicagel with benzene