Sodium Hydroxide → (2S,3E)-4-Bromo-1-(4-fluorophenoxy)but-3-en-2-ol

Participants

Reaction Conditions

Reaction Steps

AlCl3 (2.79 g, 21 mmol) was added in portions to a mixture of lithium aluminum hydride (LAH) (1.06 g, 28 mmol) and ether (70 mL). A solution of (3S)-1-bromo-4-(4-fluorophenoxy)-3-hydroxy-1-butyne (14 mmol) in ether (10 mL) was added cautiously. A vigorous reaction with evolution of gas was observed. The mixture was warmed to reflux on a water bath for 30 minutes. The reaction mixture was then cooled to 0° C. and treated with 2.8 mL water (slowly, vigorous reaction), 2.8 mL 15% NaOH, and finally 8.4 mL water. The resulting suspension was then stirred 10 minutes, filtered and the solids were washed with THF and ether. The solution was concentrated under vacuum to afford 2.94 g (81% yield for two steps) of (1E,3S)-1-bromo-4-(4-fluorophenoxy)-3-hydroxy-1-butene, a compound of formula (DD); 1H NMR (CDCl3) δ 2.41 (t, 1H), 3.85 (dd, 1H), 3.99 (dd, 1H), 4.50 (m, 1H), 6.31 (dd, 1H), 6.52 (dd, 1H), 6.83 (m, 2H), 6.97 (t, 2H) ppm.

Provenance & Evidence