Acetyl chloride → 4-(Tetrahydro-pyran-2-yloxy)-but-3-yn-2-one

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere tetrahydro-2-(2-propynyloxy)-2H-pyran (636 mL, 4.52 mmol) was dissolved in dry tetrahydrofuran (20 mL) and cooled to −78° C. n-Butyllithium (2.5 M in hexanes, 2.03 mL, 5.06 mmol) was added drop-wise. Zinc chloride (629 mg, 4.51 mmol) dissolved in tetrahydrofuran (5 mL) was added drop-wise and the reaction mixture was allowed to warm to 0° C. Acetyl chloride (0.35 mL, 4.93 mmol) was added followed by heating to 40 CC for 45 min. The reaction was quenched with saturated aqueous ammonium chloride. Ethyl acetate was added and the phases were separated. The organic phase was washed with saturated aqueous ammonium chloride (2×) and brine, dried over magnesium sulphate, filtered and concentrated in vacuo to give 4-(tetrahydro-pyran-2-yloxy)-but-3-yn-2-on as the crude product.

Provenance & Evidence