丙醛,3-(乙酰氧基) -

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

实验步骤: Charge a round-bottom flask with tin(II) chloride (16.6 g, 0.088 mol), purge with nitrogen, and add dichloroethane (300 mL) by cannula. Add ethyl diazoacetate (92 mL, 0.88 mol) by cannula and stir 10 min. Add a solution of acetic acid 3-oxo-propyl ester (0.44 mol) in CH2Cl2 (600 mL) slowly by cannula over 1 h, then stir the reaction in a 50° C. oil bath for 3 h. Concentrate under vacuum, add saturated aqueous NaHCO3 and remove the organic phase. Extract the aqueous portion with EtOAc (2×). Wash the combined organic portions with brine, dry over MgSO4, filter through Celite®, and concentrate under vacuum. Purify by flash chromatography on silica gel, eluting with a gradient of EtOAc/hexane 8%-25% to give the title compound (27.8 g, 31%), exact mass 202.08, mass spectrum (ES) 225.1 (M+Na). 1H NMR (CDCl3): δ 4.34 (t, J=6.1 Hz, 2H), 4.20 (q, J=7.1 Hz, 2H), 3.46 (s, 2H), 2.89 (t, J=6.1 Hz, 2H), 2.03 (s, 3H), 1.28 (t, J=7.1 Hz, 3H). purge with nitrogen add dichloroethane (300 mL) by cannula the reaction in a 50° C. oil bath for 3 h Concentrate under vacuum add saturated aqueous NaHCO3 remove the organic phase Extract the aqueous portion with EtOAc (2×) Wash the combined organic portions with brine dry over MgSO4 filter through Celite® concentrate under vacuum Purify by flash chromatography on silica gel eluting with a gradient of EtOAc/hexane 8%-25%

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

实验步骤: Charge a round-bottom flask with tin(II) chloride (16.6 g, 0.088 mol), purge with nitrogen, and add dichloroethane (300 mL) by cannula. Add ethyl diazoacetate (92 mL, 0.88 mol) by cannula and stir 10 min. Add a solution of acetic acid 3-oxo-propyl ester (0.44 mol) in CH2Cl2 (600 mL) slowly by cannula over 1 h, then stir the reaction in a 50° C. oil bath for 3 h. Concentrate under vacuum, add saturated aqueous NaHCO3 and remove the organic phase. Extract the aqueous portion with EtOAc (2×). Wash the combined organic portions with brine, dry over MgSO4, filter through Celite®, and concentrate under vacuum. Purify by flash chromatography on silica gel, eluting with a gradient of EtOAc/hexane 8%-25% to give the title compound (27.8 g, 31%), exact mass 202.08, mass spectrum (ES) 225.1 (M+Na). 1H NMR (CDCl3): δ 4.34 (t, J=6.1 Hz, 2H), 4.20 (q, J=7.1 Hz, 2H), 3.46 (s, 2H), 2.89 (t, J=6.1 Hz, 2H), 2.03 (s, 3H), 1.28 (t, J=7.1 Hz, 3H). purge with nitrogen add dichloroethane (300 mL) by cannula the reaction in a 50° C. oil bath for 3 h Concentrate under vacuum add saturated aqueous NaHCO3 remove the organic phase Extract the aqueous portion with EtOAc (2×) Wash the combined organic portions with brine dry over MgSO4 filter through Celite® concentrate under vacuum Purify by flash chromatography on silica gel eluting with a gradient of EtOAc/hexane 8%-25%