3-乙基四氢吡喃酮

反应条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a mixture of tetrahydropyran-4 one (5 g, 0.05 mol) and hexamethylphosphoramide (9 mL) in tetrahydrofuran (100 mL) was added lithium diisopropylamide (34.7 mL, 0.062 mol) dropwise at −78° C. under N2. After the addition the mixture was stirred for 0.5 h at −78° C. Iodoethane (7.78 g, 0.199 mol) was added to the mixture dropwise. The ddresulting mixture was stirred for 12 hours at room temperature. TLC (petroleum ether:ethyl acetate=4:1) indicated the reaction was not complete, the mixture was quenched with aqueous ammonium chloride (100 mL), extracted with ethyl acetate (3×50 mL), the combined organic layers was concentrated in vacuo and the residue was purified by chromatography on silica using petroleum ether: ethyl acetate from 15:1 to 10:1 to yield compound the title compound (2.5 g, 39.1%) as a colorless liquid. 1H NMR (400 MHz, CD3OD) δ (ppm): 4.15 (m, 2H), 3.80 (m, 1H), 3.45 (m, 1H), 2.58 (m, 1H), 2.48 (m, 2H), 1.81 (m, 1H), 1.30 (m, 1H), 0.92 (m, 3H). After the addition the mixture The ddresulting mixture was stirred for 12 hours at room temperature the mixture was quenched with aqueous ammonium chloride (100 mL) extracted with ethyl acetate (3×50 mL) the combined organic layers was concentrated in vacuo the residue was purified by chromatography on silica