1-(5-Methyl-1,2-oxazol-3-yl)ethan-1-one → 2-(5-Methylisoxazol-3-yl)but-3-yn-2-ol
Reaction equation
[C:1]([Mg]Br)#[CH:2].[CH3:5][C:6]1[O:10][N:9]=[C:8]([C:11](=[O:13])[CH3:12])[CH:7]=1>O1CCCC1>[CH3:5][C:6]1[O:10][N:9]=[C:8]([C:11]([OH:13])([C:1]#[CH:2])[CH3:12])[CH:7]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a stirred solution of ethynylmagnesium bromide (0.5 M in THF, 50 mL, 25 mmol) maintained under nitrogen below 0° C. was added a solution of 1-(5-methyl-1,2-oxazol-3-yl)ethan-1-one (2.5 g, 19.98 mmol) in tetrahydrofuran (20 mL) dropwise over 5 min. The resulting solution was warmed to room temperature and then stirred for a further 3 hr. The reaction was quenched by the addition of saturated ammonium chloride solution (100 mL) then extracted with ethyl acetate (2×100 mL). The combined organic layers was washed with brine (200 mL), dried with anhydrous sodium sulphate and concentrated in vacuo. The residue was purified on a silica gel column, elution with ethyl acetate/petroleum ether (0:1-1:4) afforded the title compound (2.3 g, 75%) as a colorless oil: 1H NMR (300 MHz, CDCl3) delta 6.12 (s, 1H), 3.47 (s, 1H), 2.63 (s, 1H), 2.42 (s, 3H), 1.86 (s, 3H).