ethyl 3-oxo-3-(oxolan-3-yl)propanoate

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

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-oxo-3-(tetrahydro-furan-3-yl)-propionic acid ethyl ester (4.0 g, 21.5 mmol) and guanidine hydrochloride (2.6 g, 27.2 mmol) in MeOH (125 mL) at 23° C. was added potassium tert-butoxide in portions (3.4 g, 30.3 mmol) over 5 min. The reaction was heated at 80° C. for 18 h. The mixture was filtered while warm to remove insoluble salts, and the filtrate was concentrated to afford an oil which was diluted with water (˜25 mL) and extracted with EtOAc (8×50 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a residue. The aqueous portion was concentrated to afford a solid residue that was collected and rinsed with MeOH. The residue and solid materials were combined and chromatographed (2 M NH3 in MeOH/EtOAc) to provide 2.02 g of product as a white solid (51%). MS (ESI): mass calcd. for: C8H11N3O2, 181.1; m/z found, 182.2 [M+H]+. 1H NMR (CD3OD): 5.66 (br s, 1H), 3.93-4.01 (m, 2H), 3.75-3.85 (m, 2H), 3.28-3.31 (m, 2H), 3.16-3.24 (m, 1H), 2.18-2.27 (m, 1H), 2.05-2.15 (m, 1H). The mixture was filtered while warm to remove insoluble salts the filtrate was concentrated to afford an oil which extracted with EtOAc (8×50 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a residue The aqueous portion was concentrated to afford a solid residue that was collected rinsed with MeOH chromatographed (2 M NH3 in MeOH/EtOAc)

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-oxo-3-(tetrahydro-furan-3-yl)-propionic acid ethyl ester (4.0 g, 21.5 mmol) and guanidine hydrochloride (2.6 g, 27.2 mmol) in MeOH (125 mL) at 23° C. was added potassium tert-butoxide in portions (3.4 g, 30.3 mmol) over 5 min. The reaction was heated at 80° C. for 18 h. The mixture was filtered while warm to remove insoluble salts, and the filtrate was concentrated to afford an oil which was diluted with water (˜25 mL) and extracted with EtOAc (8×50 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a residue. The aqueous portion was concentrated to afford a solid residue that was collected and rinsed with MeOH. The residue and solid materials were combined and chromatographed (2 M NH3 in MeOH/EtOAc) to provide 2.02 g of product as a white solid (51%). MS (ESI): mass calcd. for: C8H11N3O2, 181.1; m/z found, 182.2 [M+H]+. 1H NMR (CD3OD): 5.66 (br s, 1H), 3.93-4.01 (m, 2H), 3.75-3.85 (m, 2H), 3.28-3.31 (m, 2H), 3.16-3.24 (m, 1H), 2.18-2.27 (m, 1H), 2.05-2.15 (m, 1H). The mixture was filtered while warm to remove insoluble salts the filtrate was concentrated to afford an oil which extracted with EtOAc (8×50 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a residue The aqueous portion was concentrated to afford a solid residue that was collected rinsed with MeOH chromatographed (2 M NH3 in MeOH/EtOAc)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-oxo-3-(tetrahydro-furan-3-yl)-propionic acid ethyl ester (4.0 g, 21.5 mmol) and guanidine hydrochloride (2.6 g, 27.2 mmol) in MeOH (125 mL) at 23° C. was added potassium tert-butoxide in portions (3.4 g, 30.3 mmol) over 5 min. The reaction was heated at 80° C. for 18 h. The mixture was filtered while warm to remove insoluble salts, and the filtrate was concentrated to afford an oil which was diluted with water (˜25 mL) and extracted with EtOAc (8×50 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a residue. The aqueous portion was concentrated to afford a solid residue that was collected and rinsed with MeOH. The residue and solid materials were combined and chromatographed (2 M NH3 in MeOH/EtOAc) to provide 2.02 g of product as a white solid (51%). MS (ESI): mass calcd. for: C8H11N3O2, 181.1; m/z found, 182.2 [M+H]+. 1H NMR (CD3OD): 5.66 (br s, 1H), 3.93-4.01 (m, 2H), 3.75-3.85 (m, 2H), 3.28-3.31 (m, 2H), 3.16-3.24 (m, 1H), 2.18-2.27 (m, 1H), 2.05-2.15 (m, 1H). The mixture was filtered while warm to remove insoluble salts the filtrate was concentrated to afford an oil which extracted with EtOAc (8×50 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a residue The aqueous portion was concentrated to afford a solid residue that was collected rinsed with MeOH chromatographed (2 M NH3 in MeOH/EtOAc)

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-oxo-3-(tetrahydro-furan-3-yl)-propionic acid ethyl ester (4.0 g, 21.5 mmol) and guanidine hydrochloride (2.6 g, 27.2 mmol) in MeOH (125 mL) at 23° C. was added potassium tert-butoxide in portions (3.4 g, 30.3 mmol) over 5 min. The reaction was heated at 80° C. for 18 h. The mixture was filtered while warm to remove insoluble salts, and the filtrate was concentrated to afford an oil which was diluted with water (˜25 mL) and extracted with EtOAc (8×50 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a residue. The aqueous portion was concentrated to afford a solid residue that was collected and rinsed with MeOH. The residue and solid materials were combined and chromatographed (2 M NH3 in MeOH/EtOAc) to provide 2.02 g of product as a white solid (51%). MS (ESI): mass calcd. for: C8H11N3O2, 181.1; m/z found, 182.2 [M+H]+. 1H NMR (CD3OD): 5.66 (br s, 1H), 3.93-4.01 (m, 2H), 3.75-3.85 (m, 2H), 3.28-3.31 (m, 2H), 3.16-3.24 (m, 1H), 2.18-2.27 (m, 1H), 2.05-2.15 (m, 1H). The mixture was filtered while warm to remove insoluble salts the filtrate was concentrated to afford an oil which extracted with EtOAc (8×50 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a residue The aqueous portion was concentrated to afford a solid residue that was collected rinsed with MeOH chromatographed (2 M NH3 in MeOH/EtOAc)

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

Procedure: To a solution of lithium bis(trimethylsilyl)amide (1 M in hexanes; 100 mL) in THF (200 mL) at −78° C. was added dry ethyl acetate (10.8 g, 12 mL, 122.5 mmol) dropwise. After 30 min at −78° C., the mixture was treated with a solution of tetrahydro-furan-3-carboxylic acid methyl ester (6.0 g, 46.1 mmol) in THF (50 mL). After 4 h at −78° C., the reaction was quenched with satd. aq. NH4Cl, warmed to rt, and extracted with EtOAc (5×75 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a colorless oil. Chromatography on SiO2 (EtOAc/CH2Cl2) afforded the title compound (3.3 g). After 4 h at −78° C. the reaction was quenched with satd extracted with EtOAc (5×75 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a colorless oil

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-oxo-3-(tetrahydro-furan-3-yl)-propionic acid ethyl ester (4.0 g, 21.5 mmol) and guanidine hydrochloride (2.6 g, 27.2 mmol) in MeOH (125 mL) at 23° C. was added potassium tert-butoxide in portions (3.4 g, 30.3 mmol) over 5 min. The reaction was heated at 80° C. for 18 h. The mixture was filtered while warm to remove insoluble salts, and the filtrate was concentrated to afford an oil which was diluted with water (˜25 mL) and extracted with EtOAc (8×50 mL). The combined organic layers were washed with satd. aq. NaCl, dried, and concentrated to give a residue. The aqueous portion was concentrated to afford a solid residue that was collected and rinsed with MeOH. The residue and solid materials were combined and chromatographed (2 M NH3 in MeOH/EtOAc) to provide 2.02 g of product as a white solid (51%). MS (ESI): mass calcd. for: C8H11N3O2, 181.1; m/z found, 182.2 [M+H]+. 1H NMR (CD3OD): 5.66 (br s, 1H), 3.93-4.01 (m, 2H), 3.75-3.85 (m, 2H), 3.28-3.31 (m, 2H), 3.16-3.24 (m, 1H), 2.18-2.27 (m, 1H), 2.05-2.15 (m, 1H). The mixture was filtered while warm to remove insoluble salts the filtrate was concentrated to afford an oil which extracted with EtOAc (8×50 mL) The combined organic layers were washed with satd aq. NaCl, dried concentrated to give a residue The aqueous portion was concentrated to afford a solid residue that was collected rinsed with MeOH chromatographed (2 M NH3 in MeOH/EtOAc)