ethyl 3-oxododecanoate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: The resulting 5-decanoyl-2,2-dimethyl-1,3-dioxane-4,6-dione was allowed to reflux in ethanol for 2 hours, and then concentrated under reduced pressure. The resulting residue was purified using silica gel chromatography (developing solvent: n-hexane/ethyl acetate=3/7) to obtain the ethyl 3-oxododecanoate shown by the formula below. concentrated under reduced pressure The resulting residue was purified

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: The mixture of ethyl 3-oxododecanoate (1.456 g, ca. 5 mmol), ethylene glycol (2.78 mL, 50 mmol) and a catalytic amount of p-TsOH (95 mg, 0.5 mmol) in benzene (50 mL) was heated to 110° C. under an argon atmosphere overnight. The solvent was removed, and the residue was diluted with 50 mL ethyl acetate. The solution was washed with saturated aqueous NaHCO3 (50 mL) and brine (50 mL), and the organic phase was dried over MgSO4 and concentrated. The residue was purified by flash chromatography (hexane/EtOAc 8:1, Rf=0.21) to give ethyl 3,3-ethylenedioxydodecanoate (1.131 g, 3.95 mmol) in 79% overall yield for the above two steps. 1H NMR (500 MHz, CDCl3) δ 0.88 (t, J=7 Hz, 3H), 1.20-1.44 (m, 17H), 1.76-1.82 (m, 2H), 2.65 (s, 2H), 3.94-4.04 (m, 4H), 4.16 (q, J=7 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ 14.1, 22.6, 23.4, 29.22, 29.43, 29.48, 29.62, 31.8, 37.7, 42.5, 60.4, 65.0, 109.4, 169.5. The solvent was removed the residue was diluted with 50 mL ethyl acetate The solution was washed with saturated aqueous NaHCO3 (50 mL) and brine (50 mL) the organic phase was dried over MgSO4 concentrated The residue was purified by flash chromatography (hexane/EtOAc 8:1, Rf=0.21)

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A stirred solution of monoethyl malonate (1.26 g, 9.6 mmol) in 25 mL anhydrous THF was cooled to −78° C. under an argon atmosphere, and n-BuLi (2.5 M, 8 mL, 20 mmol) was added drop-wise via an air-tight syringe. After the addition, the temperature was raised to 0° C., and the stirring was continued for 1 hour. The mixture was then re-cooled to −78° C., and decanoyl chloride (1.044 mL, 5 mmol) was added drop-wise via an air-tight syringe. The mixture was stirred for one hour at −78° C., 30 minutes at 0° C. and 30 minutes at room temperature. The solvent was removed under reduced pressure, and the residue was re-dissolved in 50 mL ethyl acetate. The solution was washed with 1 M HCl (100 mL), saturated aqueous NaHCO3 (50 mL), and brine (50 mL). The organic layer was dried over MgSO4 and concentrated to give ethyl 3-oxododecanoate (1.456 g). The crude product was used for the next reaction. 1H NMR (500 MHz, CDCl3) δ 0.88 (t, J=7 Hz, 3H), 1.20-1.38 (m, 12H), 1.50-1.68 (m, 2H), 2.53 (t, J=7.5 Hz, 2H), 3.43 (s, 2H), 4.20 (q, J=7 Hz, 2H); 13C NMR (125 MHz, CDCl3) δ 13.975, 13.988, 22.5, 23.4, 28.91, 29.14, 29.26, 29.29, 31.8, 42.9, 49.2, 61.2, 167.2, 202.9. After the addition The mixture was then re-cooled to −78° C. The solvent was removed under reduced pressure the residue was re-dissolved in 50 mL ethyl acetate The solution was washed with 1 M HCl (100 mL), saturated aqueous NaHCO3 (50 mL), and brine (50 mL) The organic layer was dried over MgSO4 concentrated