(3R)-1-bromo-3,7-dimethyloctane

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

Procedure: A mixture of 2.33 g. (0.097 mole) of powdered magnesium and a few iodine crystals in 23 ml. of dry tetrahydrofuran was stirred at reflux temperature while a solution of 17.9 g. (0.08 mole) of (R)-(-)-1-bromo-3,7-dimethyloctane in 51 ml. of dry tetrahydrofuran was added dropwise over 1 hour. The mixture was stirred at reflux for an additional 1 hour then cooled to room temperature. To a solution of 19.5 g. (0.065 mole) of (S)-(+)-3-tert. butoxy-2-methyl-1-propyl p-toluenesulfonate in 56 ml. of dry tetrahydrofuran, stirring at -78° C. was added the R-3,7-dimethyl-1-octyl magnesium bromide solution dropwise, followed by 3.3 ml. of a 0.1 M Li2CuCl4 solution in dry tetrahydrofuran. The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) and finally for 18 hours at room temperature. At the end of this time, the reaction mixture was treated with 1 N aqueous H2SO4 and work up was carried out by extraction with ether in the manner of Example 1. The crude product was chromatographed on 450 g. of silica gel. Elution with 19:1 parts by volume hexane-ether gave the desired product which was distilled under high vacuum yielding 12.5 g. of (2R,6R)-(+)-1-tert. butoxy-2,6,10-trimethylundecane as a colorless oil, b.p. 91°-95° C. (0.3 mm Hg); [α]25D+0.94° (c 2.01, hexane). A mixture of 2.33 g at reflux temperature while a solution of 17.9 g at reflux for an additional 1 hour The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) up was carried out by extraction with ether in the manner of Example 1 The crude product was chromatographed on 450 g Elution with 19:1 parts by volume hexane-ether

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

Procedure: A mixture of 2.33 g. (0.097 mole) of powdered magnesium and a few iodine crystals in 23 ml. of dry tetrahydrofuran was stirred at reflux temperature while a solution of 17.9 g. (0.08 mole) of (R)-(-)-1-bromo-3,7-dimethyloctane in 51 ml. of dry tetrahydrofuran was added dropwise over 1 hour. The mixture was stirred at reflux for an additional 1 hour then cooled to room temperature. To a solution of 19.5 g. (0.065 mole) of (S)-(+)-3-tert. butoxy-2-methyl-1-propyl p-toluenesulfonate in 56 ml. of dry tetrahydrofuran, stirring at -78° C. was added the R-3,7-dimethyl-1-octyl magnesium bromide solution dropwise, followed by 3.3 ml. of a 0.1 M Li2CuCl4 solution in dry tetrahydrofuran. The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) and finally for 18 hours at room temperature. At the end of this time, the reaction mixture was treated with 1 N aqueous H2SO4 and work up was carried out by extraction with ether in the manner of Example 1. The crude product was chromatographed on 450 g. of silica gel. Elution with 19:1 parts by volume hexane-ether gave the desired product which was distilled under high vacuum yielding 12.5 g. of (2R,6R)-(+)-1-tert. butoxy-2,6,10-trimethylundecane as a colorless oil, b.p. 91°-95° C. (0.3 mm Hg); [α]25D+0.94° (c 2.01, hexane). A mixture of 2.33 g at reflux temperature while a solution of 17.9 g at reflux for an additional 1 hour The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) up was carried out by extraction with ether in the manner of Example 1 The crude product was chromatographed on 450 g Elution with 19:1 parts by volume hexane-ether

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

Procedure: A mixture of 2.33 g. (0.097 mole) of powdered magnesium and a few iodine crystals in 23 ml. of dry tetrahydrofuran was stirred at reflux temperature while a solution of 17.9 g. (0.08 mole) of (R)-(-)-1-bromo-3,7-dimethyloctane in 51 ml. of dry tetrahydrofuran was added dropwise over 1 hour. The mixture was stirred at reflux for an additional 1 hour then cooled to room temperature. To a solution of 19.5 g. (0.065 mole) of (S)-(+)-3-tert. butoxy-2-methyl-1-propyl p-toluenesulfonate in 56 ml. of dry tetrahydrofuran, stirring at -78° C. was added the R-3,7-dimethyl-1-octyl magnesium bromide solution dropwise, followed by 3.3 ml. of a 0.1 M Li2CuCl4 solution in dry tetrahydrofuran. The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) and finally for 18 hours at room temperature. At the end of this time, the reaction mixture was treated with 1 N aqueous H2SO4 and work up was carried out by extraction with ether in the manner of Example 1. The crude product was chromatographed on 450 g. of silica gel. Elution with 19:1 parts by volume hexane-ether gave the desired product which was distilled under high vacuum yielding 12.5 g. of (2R,6R)-(+)-1-tert. butoxy-2,6,10-trimethylundecane as a colorless oil, b.p. 91°-95° C. (0.3 mm Hg); [α]25D+0.94° (c 2.01, hexane). A mixture of 2.33 g at reflux temperature while a solution of 17.9 g at reflux for an additional 1 hour The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) up was carried out by extraction with ether in the manner of Example 1 The crude product was chromatographed on 450 g Elution with 19:1 parts by volume hexane-ether

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

Procedure: A mixture of 2.33 g. (0.097 mole) of powdered magnesium and a few iodine crystals in 23 ml. of dry tetrahydrofuran was stirred at reflux temperature while a solution of 17.9 g. (0.08 mole) of (R)-(-)-1-bromo-3,7-dimethyloctane in 51 ml. of dry tetrahydrofuran was added dropwise over 1 hour. The mixture was stirred at reflux for an additional 1 hour then cooled to room temperature. To a solution of 19.5 g. (0.065 mole) of (S)-(+)-3-tert. butoxy-2-methyl-1-propyl p-toluenesulfonate in 56 ml. of dry tetrahydrofuran, stirring at -78° C. was added the R-3,7-dimethyl-1-octyl magnesium bromide solution dropwise, followed by 3.3 ml. of a 0.1 M Li2CuCl4 solution in dry tetrahydrofuran. The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) and finally for 18 hours at room temperature. At the end of this time, the reaction mixture was treated with 1 N aqueous H2SO4 and work up was carried out by extraction with ether in the manner of Example 1. The crude product was chromatographed on 450 g. of silica gel. Elution with 19:1 parts by volume hexane-ether gave the desired product which was distilled under high vacuum yielding 12.5 g. of (2R,6R)-(+)-1-tert. butoxy-2,6,10-trimethylundecane as a colorless oil, b.p. 91°-95° C. (0.3 mm Hg); [α]25D + 0.94° (c 2.01, hexane). A mixture of 2.33 g at reflux temperature while a solution of 17.9 g at reflux for an additional 1 hour The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) up was carried out by extraction with ether in the manner of Example 1 The crude product was chromatographed on 450 g Elution with 19:1 parts by volume hexane-ether

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

Procedure: A mixture of 2.33 g. (0.097 mole) of powdered magnesium and a few iodine crystals in 23 ml. of dry tetrahydrofuran was stirred at reflux temperature while a solution of 17.9 g. (0.08 mole) of (R)-(-)-1-bromo-3,7-dimethyloctane in 51 ml. of dry tetrahydrofuran was added dropwise over 1 hour. The mixture was stirred at reflux for an additional 1 hour then cooled to room temperature. To a solution of 19.5 g. (0.065 mole) of (S)-(+)-3-tert. butoxy-2-methyl-1-propyl p-toluenesulfonate in 56 ml. of dry tetrahydrofuran, stirring at -78° C. was added the R-3,7-dimethyl-1-octyl magnesium bromide solution dropwise, followed by 3.3 ml. of a 0.1 M Li2CuCl4 solution in dry tetrahydrofuran. The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) and finally for 18 hours at room temperature. At the end of this time, the reaction mixture was treated with 1 N aqueous H2SO4 and work up was carried out by extraction with ether in the manner of Example 1. The crude product was chromatographed on 450 g. of silica gel. Elution with 19:1 parts by volume hexane-ether gave the desired product which was distilled under high vacuum yielding 12.5 g. of (2R,6R)-(+)-1-tert. butoxy-2,6,10-trimethylundecane as a colorless oil, b.p. 91°-95° C. (0.3 mm Hg); [α]25D+0.94° (c 2.01, hexane). A mixture of 2.33 g at reflux temperature while a solution of 17.9 g at reflux for an additional 1 hour The resulting mixture was stirred at -78° C. for 10 minutes, for 2 hours at 0°-5° C. (ice bath) up was carried out by extraction with ether in the manner of Example 1 The crude product was chromatographed on 450 g Elution with 19:1 parts by volume hexane-ether

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

Procedure: A Grignard solution is prepared in the manner described above in Example 10 from 0.3 g (12.4 mmol) of magnesium and 2.54 g (11.5 mmol) of (R)-1-bromo-3,7-dimethyloctane in 10 ml of absolute tetrahydrofuran. To this solution are added dropwise at 0° 1.45 g (5.57 mmol) of 2-[(S)-4-bromo-3-methylbutoxy]-tetrahydro-2H-pyran followed by 0.3 ml of a 0.1 molar solution of Li2CuCl4 in tetrahydrofuran. This reaction mixture is stirred at 0° for 3 hours. The working-up as well as the hydrolysis of the tetrahydro-2-{[(3R,7R)-3,7,11-trimethyldodecyl]-oxy}-2-H-pyran obtained to (3R,7R)-3,7,11-trimethyl-1-dodecanol is effected in the manner described above in Example 10. The yield of (3R,7R)-3,7,11-trimethyl-1-dodecanol amounts, after bulb-tube distillation at 90°-95°/0.05 Torr, to 0.5 g (43% based on 2-[ (S)-4-bromo-3-methylbutoxy]-tetrahydro-2H-pyran); [α]D20 =+3.9° (c=1.05, n-octane). A Grignard solution is prepared in the manner

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

Procedure: 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

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

Procedure: A Grignard solution is prepared in the manner described above in Example 10 from 0.3 g (12.4 mmol) of magnesium and 2.54 g (11.5 mmol) of (R)-1-bromo-3,7-dimethyloctane in 10 ml of absolute tetrahydrofuran. To this solution are added dropwise at 0° 1.45 g (5.57 mmol) of 2-[(S)-4-bromo-3-methylbutoxy]-tetrahydro-2H-pyran followed by 0.3 ml. of a 0.1 molar solution of Li2CuCl4 in tetrahydrofuran. This reaction mixture is stirred at 0° for 3 hours. The working-up as well as the hydrolysis of the tetrahydro-2-{[(3R,7R)-3,7,11-trimethyldodecyl]-oxy}-2H-pyran obtained to (3R,7R)-3,7,11-trimethyl-1-dodecanol is effected in the manner described above in Example 10. The yield of (3R,7R)-3,7,11-trimethyl-1-dodecanol amounts, after bulb-tube distillation at 90°-95°/0.05 Torr, to 0.5 g (43% based on 2-[ (S)-4-bromo-3-methylbutoxy]-tetrahydro-2H-pyran); [α]D20 = +3.9° (c = 1.05, n-octane). A Grignard solution is prepared in the manner

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

Procedure: 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