1-(5-(Hydroxymethyl)isoxazol-3-yl)ethanone → 2-[5-(Hydroxymethyl)isoxazol-3-yl]but-3-yn-2-ol

Participants

Reaction Steps

To a solution of ethynylmagnesium bromide (0.5M in THF, 99 mL, 49.0 mmol) at 0° C. under N2 was added a solution of 1-[5-(hydroxymethyl)isoxazol-3-yl]ethanone (prepared according to Synthesis 2005, 20, 3541) (4.10 g, 29.0 mmol) in dry THF (25 mL) over 20 minutes. The reaction mixture was warmed to RT for 1.5 hr, quenched by dropwise addition of saturated aqueous ammonium chloride (20 mL) and concentrated in vacuo. After re-dissolving the residue in EtOAc (100 mL), the aqueous phase was removed, diluted with water to dissolve all suspended solids and washed with EtOAc (100 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo to furnish the crude title compound as a red-brown syrup: 1H NMR (500 MHz, CDCl3) delta 1.88 (3H, s), 2.67 (1H, s), 4.77 (2H, s), 6.39 (1H, s); LC-MS: m/z=+167.9 (M+H)+. This compound, with LC-MS purity=88% UV, was used in the next step without further purification.

Provenance & Evidence