反应详情

A stirred solution of dihydro-2H-pyran-4(3H)-one (500 mg, 5.0 mmol) in dry THF (20 mL) was cooled to −70° C. and 0.5 M ethynylmagnesium chloride in THF (20 mL, 10 mmol) was added in a slow stream. The cooling bath was allowed to expire and the mixture was stirred as it warmed to rt. After 6 h, satd aq NH4Cl (20 mL) was added and the mixture was concentrated on the rotary evaporator. The aqueous residue was extracted with EtOAc (2×50 mL). The combined organic extracts were washed with brine, dried over Na2SO4 and concentrated to leave crude 4-ethynyltetrahydro-2H-pyran-4-ol (491 mg, 78%) as a brown oil. 1H NMR (CDCl3) 1.80 (m, 2H), 1.92 (m, 2H), 2.57 (s, 1H), 3.68 (m, 2H), 3.90 (m, 2H).

1. additionwas added
2. concentrationthe mixture was concentrated on the rotary evaporator
3. extractionThe aqueous residue was extracted with EtOAc (2×50 mL)
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated