Ethyl Bromide → 12-{[tert-Butyl(dimethyl)silyl]oxy}dodec-9-yn-2-ol

Participants

Reaction Steps

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.

Provenance & Evidence