تفاعل #56722

معادلة التفاعل

LiCl

(R)-3-bromo-2-methylpropanol

Magnesium

iodine

1-bromo-3-methyl butane

1-bromo-3-methyl butane

→

(R)-2,6-dimethyl heptan-1-ol

المذيبات

THF

THF

THF

THF

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe mixture was heated
2. 2
   workup.ADDITIONadded dropwise
3. 3
   درجة الحرارةcooled to −5° C
4. 4
   أخرىthe temperature below 0° C
5. 5
   workup.STIRRINGThe resulting mixture was stirred for 20 min
6. 6
   أخرىthe temperature below 0° C
7. 7
   أخرىwas allowed to slowly reach ambient temperature overnight
8. 8
   أخرىThe reaction mixture was quenched with ammonium hydroxide and water
9. 9
   workup.ADDITIONThe mixture was diluted with EtOAc
10. 10
    استخلاصextracted with 3×20 mL EtOAc
11. 11
    غسيلThe organics were washed with brine
12. 12
    تجفيفdried (MgSO4)
13. 13
    ترشيحfiltered
14. 14
    تركيزconcentrated
15. 15
    أخرىThe residual oil was purified via silica gel chromatography (90/10 Hexane/EtOAc)

الإجراء التجريبي

Magnesium turnings (2.04 g, 84 mmol) and a crystal of iodine were suspended in 5 mL THF for the addition of 1-bromo-3-methyl butane (0.3 mL, neat). The mixture was heated to start the Grignard formation. The remaining 1-bromo-3-methyl butane (8.63 mL, 72 mmol) was diluted in THF (60 mL) and added dropwise. The mixture was stirred at ambient temperature for 2 hours and cooled to −5° C. A solution of copper chloride (1.21 g, 9 mmol) and LiCl (0.76 g, 18 mmol) in THF (50 mL) was added dropwise keeping the temperature below 0° C. The resulting mixture was stirred for 20 min, and (R)-3-bromo-2-methylpropanol in THF (20 mL) was added dropwise while keeping the temperature below 0° C. The mixture was allowed to slowly reach ambient temperature overnight. The reaction mixture was quenched with ammonium hydroxide and water. The mixture was diluted with EtOAc and extracted with 3×20 mL EtOAc. The organics were washed with brine, dried (MgSO4), filtered and concentrated. The residual oil was purified via silica gel chromatography (90/10 Hexane/EtOAc) to give 2.67 g (R)-2,6-dimethyl heptan-1-ol.

المصدر