ethyl 2-(oxan-4-yl)propanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diisopropylamine (2.8 g) was dissolved in tetrahydrofuran (20 ml). A solution of n-butyllithium in hexane (2.64 N, 11 ml) was added dropwise under nitrogen atmosphere under ice-cooling, and the mixture was stirred at the same temperature for 15 minutes. The reaction solution was cooled to −78° C. A solution of ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (4.0 g) in tetrahydrofuran (15 ml) was added dropwise and the mixture was stirred at the same temperature for 15 minutes. Methyl iodide (2.2 ml) was subsequently added dropwise. The mixture was stirred at the same temperature for 10 minutes, and then warmed to room temperature and stirred for 3 hours. A 1 N aqueous hydrochloric acid solution was added under ice-cooling, followed by extraction with ethyl acetate. The organic layer was washed with a saturated aqueous sodium bicarbonate solution and brine and then dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane) to give the title compound (4.0 g) as a colorless oil. cooling the mixture was stirred at the same temperature for 15 minutes The mixture was stirred at the same temperature for 10 minutes warmed to room temperature stirred for 3 hours cooling followed by extraction with ethyl acetate The organic layer was washed with a saturated aqueous sodium bicarbonate solution and brine dried over anhydrous sodium sulfate the solvent was evaporated The residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of (Tetrahydro-pyran-4-yl)-acetic acid ethyl ester (2.0 g, 11.6 mmol) in 50 mL of THF at −78° C. LDA (1.0 M, 17.4 mL, 34.8 mmol) is added dropwise. The solution is stirred for 0.5 h and treated with HMPA (3.2 mL, 9.3 mmol) and MeI (4.94 g, 34.8 mmol). The reaction mixture is stirred at the same temperature for 0.5 h and for 1.5 h at 0° C., acidified with aqueous 1 N aqueous HCl solution, and extracted twice with ether (2×40 mL). The organic phase is washed with saturated aqueous NaCl solution, dried (MgSO4), and concentrated in vacuo to give 1.8 g of 2-(Tetrahydro-pyran-4-yl)-propionic acid ethyl ester which is hydrolyzed without further purification. A solution of the crude ester (500 mg, 2.68 mmol) and 5 N aqueous NaOH solution (2.68 mL, 13.4 mmol) in dioxane-water (4 mL/2 mL) is heated at 60° C. for 2 h. The solution is cooled to room temperature, acidified with 1 N aqueous HCl solution, and extracted with ether. The ether layer is washed with saturated aqueous NaCl solution, dried over anhydrous MgSO4, and concentrated in vacuo to give 400 mg of the title compound. MS: 159 [M+H]+; tR (HPLC, ACQUITY UPLC™ BEH C18 1.7 μm, 50×2.1 mm; 5-100% CH3CN+0.1% TFA/H2O+0.1% TFA for 2 min then 100% CH3CN+0.1% TFA for 1 min, flow 0.5 ml/min): 1.27 min. is hydrolyzed without further purification extracted with ether The ether layer is washed with saturated aqueous NaCl solution dried over anhydrous MgSO4 concentrated in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of (Tetrahydro-pyran-4-yl)-acetic acid ethyl ester (2.0 g, 11.6 mmol) in 50 mL of THF at −78° C. LDA (1.0 M, 17.4 mL, 34.8 mmol) is added dropwise. The solution is stirred for 0.5 h and treated with HMPA (3.2 mL, 9.3 mmol) and MeI (4.94 g, 34.8 mmol). The reaction mixture is stirred at the same temperature for 0.5 h and for 1.5 h at 0° C., acidified with aqueous 1 N aqueous HCl solution, and extracted twice with ether (2×40 mL). The organic phase is washed with saturated aqueous NaCl solution, dried (MgSO4), and concentrated in vacuo to give 1.8 g of 2-(Tetrahydro-pyran-4-yl)-propionic acid ethyl ester which is hydrolyzed without further purification. A solution of the crude ester (500 mg, 2.68 mmol) and 5 N aqueous NaOH solution (2.68 mL, 13.4 mmol) in dioxane-water (4 mL/2 mL) is heated at 60° C. for 2 h. The solution is cooled to room temperature, acidified with 1 N aqueous HCl solution, and extracted with ether. The ether layer is washed with saturated aqueous NaCl solution, dried over anhydrous MgSO4, and concentrated in vacuo to give 400 mg of the title compound. MS: 159 [M+H]+; tR (HPLC, ACQUITY UPLC™ BEH C18 1.7 μm, 50×2.1 mm; 5-100% CH3CN+0.1% TFA/H2O+0.1% TFA for 2 min then 100% CH3CN+0.1% TFA for 1 min, flow 0.5 ml/min): 1.27 min. at −78° C The reaction mixture is stirred at the same temperature for 0.5 h and for 1.5 h at 0° C. extracted twice with ether (2×40 mL) The organic phase is washed with saturated aqueous NaCl solution dried (MgSO4) concentrated in vacuo

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Diisopropylamine (2.8 g) was dissolved in tetrahydrofuran (20 ml). A solution of n-butyllithium in hexane (2.64 N, 11 ml) was added dropwise under nitrogen atmosphere under ice-cooling, and the mixture was stirred at the same temperature for 15 minutes. The reaction solution was cooled to −78° C. A solution of ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (4.0 g) in tetrahydrofuran (15 ml) was added dropwise and the mixture was stirred at the same temperature for 15 minutes. Methyl iodide (2.2 ml) was subsequently added dropwise. The mixture was stirred at the same temperature for 10 minutes, and then warmed to room temperature and stirred for 3 hours. A 1 N aqueous hydrochloric acid solution was added under ice-cooling, followed by extraction with ethyl acetate. The organic layer was washed with a saturated aqueous sodium bicarbonate solution and brine and then dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane) to give the title compound (4.0 g) as a colorless oil. cooling the mixture was stirred at the same temperature for 15 minutes The mixture was stirred at the same temperature for 10 minutes warmed to room temperature stirred for 3 hours cooling followed by extraction with ethyl acetate The organic layer was washed with a saturated aqueous sodium bicarbonate solution and brine dried over anhydrous sodium sulfate the solvent was evaporated The residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane)