Ethyl Bromide → 12-{[tert-Butyl(dimethyl)silyl]oxy}dodec-9-yn-2-ol
Reaction equation
[Mg].[O:2]([CH2:10][CH2:11][C:12]#[C:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18]I)[Si:3]([C:6]([CH3:9])([CH3:8])[CH3:7])([CH3:5])[CH3:4].C(Br)C.[CH2:23]1[O:26][CH:24]1[CH3:25]>C1COCC1>[O:2]([CH2:10][CH2:11][C:12]#[C:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:23][CH:24]([OH:26])[CH3:25])[Si:3]([C:6]([CH3:9])([CH3:8])[CH3:7])([CH3:5])[CH3:4]Participants
Procedure
To magnesium powder (830 mg, 35 mmol) and 18 (8.7 g, 23 mmol) in 40 mL of dry THF under nitrogen was added ethyl bromide (0.1 mL,=1.3 mmol). Grignard formation was maintained by refluxing for 3 hr. After the iodide (18) was consumed, 2.2 g (11.5 mmol) of cuprous iodide was added. The mixture was cooled in an ice-bath and stirred for 30 min. Propylene oxide (2.7 g, 46 mmol) diluted in 10 mL of dry THF was added dropwise, the reaction stirred for 30 min at 23° C. and then quenched with saturated aqueous ammonium chloride (100 mL). The ether extract (3×75 mL) of the aqueous mixture was washed with brine (3×75 mL). The isolated product was purified by chromatography9 on 180 g (20 cm×4.5 cm I.D. column) of silica gel (20% EtOAc in hexane) to give 3.3 g (46% yield) of 19.
Workup
- temperatureGrignard formation was maintained
- temperatureby refluxing for 3 hr
- customAfter the iodide (18) was consumed
- temperatureThe mixture was cooled in an ice-bath
- additionwas added dropwise
- stirringthe reaction stirred for 30 min at 23° C.
- customquenched with saturated aqueous ammonium chloride (100 mL)
- extractionThe ether extract (3×75 mL) of the aqueous mixture
- washwas washed with brine (3×75 mL)
- customThe isolated product was purified by chromatography9 on 180 g (20 cm×4.5 cm I.D. column) of silica gel (20% EtOAc in hexane)
Sources & evidence
- ORD record
- ord-a98d116585d04b90af80c45dc8e27c1c
- Source dataset
- uspto-grants-1985_12
- Patent number
- US04560551
Reaction notes
Loading…