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

Participants

Reaction Steps

To a solution of 1-[5-(methoxymethyl)isoxazol-3-yl]ethanone (220 mg, 1.42 mmol) in dry THF (4 mL) at 0° C. under an atmosphere of nitrogen, was introduced ethynylmagnesium bromide (4.4 mL of a 0.5M solution in THF, 2.20 mmol) dropwise over 5 min. After 1.5 hr at this temperature, the reaction was carefully quenched with water (0.2 mL) and the resulting suspension concentrated in vacuo. The residual syrup was slurried in water (5 mL) and the pH adjusted to 2 with 5M aqueous hydrochloric acid for 5 min., then saturated sodium bicarbonate solution introduced until the pH was ˜7.5. Following extraction of the basic aqueous solution with EtOAc (2×100 ml), the combined EtOAc extracts were dried (Na2SO4), filtered and the filtrate concentrated in vacuo to furnish the crude title compound as a pale brown oil: 1H NMR (500 MHz, CDCl3) delta 1.89 (3H, s), 2.66 (1H, s), 3.02 (1H, br. s), 3.45 (3H, s), 4.55 (2H, s), 6.39 (1H, s); LC-MS: m/z=+181.95 (M+H)+.

Provenance & Evidence