反応 #162902
ord-4c121ae39c6c4343a606dfc469e06419
反応方程式
反応条件
後処理
- 1その他A 3-neck 1-L round bottom flask was equipped with a thermometer
- 2温度cooled
- 3workup.WAITThe mixture was left in the cooling bath
- 4その他to regain room temperature
- 5温度The mixture was then cooled to −5° C.
- 6その他quenched by the slow addition of water (40 mL)
- 7workup.STIRRINGunder vigorous stirring over 1.5 hours
- 8温度to maintain the internal temperature below 30° C
- 9workup.ADDITIONTo this was added drop-wise 15% NaOH (40 mL) and water (40 mL)
- 10ろ過The resulting precipitate was filtered over Celite
- 11洗浄washed with THF (300 mL)
- 12濃縮The filtrate was concentrated in vacuo to dryness
実験手順
A 3-neck 1-L round bottom flask was equipped with a thermometer, dropping funnel and nitrogen inlet. Under an atmosphere of N2, a solution of 1M lithium aluminum hydride in THF (900 mL, 900 mmol) was added and cooled using a dry ice/acetone bath. To this was added drop-wise a solution of diethyl 1,4-dioxaspiro[4.5]decane-8,8-dicarboxylate, Intermediate 3, (128.7 g, 450 mmol) in THF (75 mL) over a period of 1 h while maintaining the internal temperature at 10-15° C. The mixture was left in the cooling bath and allowed to regain room temperature while stirring overnight. The mixture was then cooled to −5° C. and quenched by the slow addition of water (40 mL) under vigorous stirring over 1.5 hours being careful to maintain the internal temperature below 30° C. To this was added drop-wise 15% NaOH (40 mL) and water (40 mL). The resulting precipitate was filtered over Celite, and washed with THF (300 mL). The filtrate was concentrated in vacuo to dryness to provide the title compound (63.3 g) as a white solid. Further extraction of the white cake with 10% MeOH/CH2Cl2 (2×500 mL) gave an additional amount (15.6 g) of the title compound. This constitutes total combined yield of 78.9 g (0.39 mol, Y. 87%). LCMS: m/z 203 (M+H), 225 (M+Na). 1HNMR (500 MHz, CD3OD) δ ppm 1.49-1.55 (4H, m, 3,5-CH2), 1.59-1.66 (4H, m, 2,6-CH2), 3.49 (4H, s, 9,10-OCH2), 3.94 (4H, s, 7,8-OCH2). 13C NMR (126 MHz, CD3OD) δ ppm 26.7 (3,5-CH2), 30.3 (2,6-CH2), 38.3 (4-C), 64.2 (7,8-OCH2), 65.4 (9,10-OCH2), 109.2 (1-OCO).