ethynylcyclopentane

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

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: To a stirred solution of cyclopentylacetylene (7, 17.49 mL, 150.0 mmol) in anhydrous tetrahydrofuran (THF, 200 mL, 2466 mmol) at −78° C. was added 2.50 M of n-butyllithium in hexane (66.0 mL, 165 mmol, 1.1 equiv). The resulting milky suspension was stirred at −78° C. for 30 min. Methyl chloroformate (17.6 mL, 225 mmol, 1.5 equiv) was then added. The reaction mixture became a clear solution. The cooling bath was then removed, and the reaction mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The reaction mixture became a suspension again. When TLC (5% EtOAc/hexane, KMnO4 stain) showed the reaction was deemed complete, the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) and extracted with diethyl ether (Et2O, 2×200 mL). The combined organic layers were washed with saturated aqueous NaCl solution, dried over magnesium sulfate (MgSO4), filtered and concentrated under the reduced pressure. The residue was distilled under vacuum (99-101° C./16 mbar) to afford methyl 3-cyclopentylpropiolate (18, 21.856 g, 22.83 g theoretical, 96% yield) as a colorless oil. For 18: 1H NMR (CDCl3, 400 MHz) δ ppm 3.74 (s, 3H), 2.73 (m, 1H), 1.95 (m, 2H), 1.72 (m, 4H), 1.57 (m, 2H). The cooling bath was then removed to warm to room temperature stirred at room temperature for 1 h the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) extracted with diethyl ether (Et2O, 2×200 mL) The combined organic layers were washed with saturated aqueous NaCl solution dried over magnesium sulfate (MgSO4) filtered concentrated under the reduced pressure The residue was distilled under vacuum (99-101° C./16 mbar)

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

Procedure: To a oven dried 500 mL 3-neck round bottom flask equipped with a stir bar, a nitrogen inlet, a 125 mL addition funnel and a thermocouple, cyclopentylacetylene (7, 15.0 g, 0.143 mol) and anhydrous tetrahydrofuran (THF, 170 mL, 2.10 mol) were added at room temperature. The resulting solution was then cooled to −78° C. before a solution of 2.5 M n-butyllithium in hexane (63.1 mL, 0.158 mol, 1.1 equiv) was added dropwise over 25 min. The resulting lithium cyclopentylacetylene solution was stirred at −78° C. for 15 minutes before a solution of crude cyanatobenzene (6, 25.0 g, 0.210 mol, 1.5 equiv) in anhydrous tetrahydrofuran (THF, 30.0 mL, 0.400 mol) was added dropwise via a canula at −78° C. The resulting reaction mixture was stirred at −78° C. for an additional 10 min before the cooling batch was removed and the reaction mixture was allowed to gradually warm to room temperature and stirred at room temperature for 1-2 h. When the reaction was deemed complete, the reaction mixture was quenched with a 6 N aqueous sodium hydroxide solution (NaOH, 200 mL) and a 20% aqueous brine solution (200 mL). The aqueous solution was treated with ethyl acetate (EtOAc, 200 mL) before the two layers were separated. The organic layer was dried over magnesium sulfate (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by flash column chromatography (SiO2, 0 to 5% ethyl acetate/hexane gradient elution) to afford 3-cyclopentylpropiolonitrile (8, 14.3 g, 17.0 g theoretical, 84% yield for two steps) as a yellow to orange oil. For 8: 1H NMR (DMSO-d6, 400 MHz) δ 2.97 (m, 1H), 1.97 (m, 2H), 1.64 (m, 4H), 1.56 (m, 2H). To a oven dried 500 mL 3-neck round bottom flask equipped with a stir bar, a nitrogen inlet, a 125 mL addition funnel was added dropwise over 25 min was added dropwise via a canula at −78° C The resulting reaction mixture was removed to gradually warm to room temperature stirred at room temperature for 1-2 h the reaction mixture was quenched with a 6 N aqueous sodium hydroxide solution (NaOH, 200 mL) The aqueous solution was treated with ethyl acetate (EtOAc, 200 mL) before the two layers were separated The organic layer was dried over magnesium sulfate (MgSO4) filtered concentrated under reduced pressure The residue was purified by flash column chromatography (SiO2, 0 to 5% ethyl acetate/hexane gradient elution)

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

Procedure: The title compound was prepared from ethynyl-cyclopentane and ethyl chloroformate in accordance with the procedures of G. Cai et al., Tetrahedron, 2006, 5697-5708.

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

Procedure: Coupling of ethynylcyclopentane (40) with tert-butyl 3-(3-bromophenyl)-3-hydroxypropylcarbamate (39) following the method used in the synthesis of Example 13 gave tert-butyl 3-(3-(cyclopentylethynyl)phenyl)-3-hydroxypropylcarbamate (41) as a brown oil. Yield (0.386 g, 92%). used in the synthesis of Example 13

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

Procedure: Coupling of ethynylcyclopentane (40) with tert-butyl 3-(3-bromophenyl)-3-hydroxypropylcarbamate (39) following the method used in the synthesis of Example 13 gave tert-butyl 3-(3-(cyclopentylethynyl)phenyl)-3-hydroxypropylcarbamate (41) as a brown oil. Yield (0.386 g, 92%). used in the synthesis of Example 13

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

Procedure: To a stirred solution of cyclopentylacetylene (7, 17.49 mL, 150.0 mmol) in anhydrous tetrahydrofuran (THF, 200 mL, 2466 mmol) at −78° C. was added 2.50 M of n-butyllithium in hexane (66.0 mL, 165 mmol, 1.1 equiv). The resulting milky suspension was stirred at −78° C. for 30 min. Methyl chloroformate (17.6 mL, 225 mmol, 1.5 equiv) was then added. The reaction mixture became a clear solution. The cooling bath was then removed, and the reaction mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The reaction mixture became a suspension again. When TLC (5% EtOAc/hexane, KMnO4 stain) showed the reaction was deemed complete, the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) and extracted with diethyl ether (Et2O, 2×200 mL). The combined organic layers were washed with saturated aqueous NaCl solution, dried over magnesium sulfate (MgSO4), filtered and concentrated under the reduced pressure. The residue was distilled under vacuum (99-101° C./16 mbar) to afford methyl 3-cyclopentylpropiolate (18, 21.856 g, 22.83 g theoretical, 96% yield) as a colorless oil. For 18: 1H NMR (CDCl3, 400 MHz) δ ppm 3.74 (s, 3H), 2.73 (m, 1H), 1.95 (m, 2H), 1.72 (m, 4H), 1.57 (m, 2H). The cooling bath was then removed to warm to room temperature stirred at room temperature for 1 h the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) extracted with diethyl ether (Et2O, 2×200 mL) The combined organic layers were washed with saturated aqueous NaCl solution dried over magnesium sulfate (MgSO4) filtered concentrated under the reduced pressure The residue was distilled under vacuum (99-101° C./16 mbar)

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

Procedure: To a stirred solution of cyclopentylacetylene (7, 17.49 mL, 150.0 mmol) in anhydrous tetrahydrofuran (THF, 200 mL, 2466 mmol) at −78° C. was added 2.50 M of n-butyllithium in hexane (66.0 mL, 165 mmol, 1.1 equiv). The resulting milky suspension was stirred at −78° C. for 30 min. Methyl chloroformate (17.6 mL, 225 mmol, 1.5 equiv) was then added. The reaction mixture became a clear solution. The cooling bath was then removed, and the reaction mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The reaction mixture became a suspension again. When TLC (5% EtOAc/hexane, KMnO4 stain) showed the reaction was deemed complete, the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) and extracted with diethyl ether (Et2O, 2×200 mL). The combined organic layers were washed with saturated aqueous NaCl solution, dried over magnesium sulfate (MgSO4), filtered and concentrated under the reduced pressure. The residue was distilled under vacuum (99-101° C./16 mbar) to afford methyl 3-cyclopentylpropiolate (18, 21.856 g, 22.83 g theoretical, 96% yield) as a colorless oil. For 18: 1H NMR (CDCl3, 400 MHz) δ ppm 3.74 (s, 3H), 2.73 (m, 1H), 1.95 (m, 2H), 1.72 (m, 4H), 1.57 (m, 2H). The cooling bath was then removed to warm to room temperature stirred at room temperature for 1 h the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) extracted with diethyl ether (Et2O, 2×200 mL) The combined organic layers were washed with saturated aqueous NaCl solution dried over magnesium sulfate (MgSO4) filtered concentrated under the reduced pressure The residue was distilled under vacuum (99-101° C./16 mbar)

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

Procedure: To a oven dried 500 mL 3-neck round bottom flask equipped with a stir bar, a nitrogen inlet, a 125 mL addition funnel and a thermocouple, cyclopentylacetylene (7, 15.0 g, 0.143 mol) and anhydrous tetrahydrofuran (THF, 170 mL, 2.10 mol) were added at room temperature. The resulting solution was then cooled to −78° C. before a solution of 2.5 M n-butyllithium in hexane (63.1 mL, 0.158 mol, 1.1 equiv) was added dropwise over 25 min. The resulting lithium cyclopentylacetylene solution was stirred at −78° C. for 15 minutes before a solution of crude cyanatobenzene (6, 25.0 g, 0.210 mol, 1.5 equiv) in anhydrous tetrahydrofuran (THF, 30.0 mL, 0.400 mol) was added dropwise via a canula at −78° C. The resulting reaction mixture was stirred at −78° C. for an additional 10 min before the cooling batch was removed and the reaction mixture was allowed to gradually warm to room temperature and stirred at room temperature for 1-2 h. When the reaction was deemed complete, the reaction mixture was quenched with a 6 N aqueous sodium hydroxide solution (NaOH, 200 mL) and a 20% aqueous brine solution (200 mL). The aqueous solution was treated with ethyl acetate (EtOAc, 200 mL) before the two layers were separated. The organic layer was dried over magnesium sulfate (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by flash column chromatography (SiO2, 0 to 5% ethyl acetate/hexane gradient elution) to afford 3-cyclopentylpropiolonitrile (8, 14.3 g, 17.0 g theoretical, 84% yield for two steps) as a yellow to orange oil. For 8: 1H NMR (DMSO-d6, 400 MHz) δ 2.97 (m, 1H), 1.97 (m, 2H), 1.64 (m, 4H), 1.56 (m, 2H). To a oven dried 500 mL 3-neck round bottom flask equipped with a stir bar, a nitrogen inlet, a 125 mL addition funnel was added dropwise over 25 min was added dropwise via a canula at −78° C The resulting reaction mixture was removed to gradually warm to room temperature stirred at room temperature for 1-2 h the reaction mixture was quenched with a 6 N aqueous sodium hydroxide solution (NaOH, 200 mL) The aqueous solution was treated with ethyl acetate (EtOAc, 200 mL) before the two layers were separated The organic layer was dried over magnesium sulfate (MgSO4) filtered concentrated under reduced pressure The residue was purified by flash column chromatography (SiO2, 0 to 5% ethyl acetate/hexane gradient elution)

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

Procedure: To a stirred solution of cyclopentylacetylene (7, 17.49 mL, 150.0 mmol) in anhydrous tetrahydrofuran (THF, 200 mL, 2466 mmol) at −78° C. was added 2.50 M of n-butyllithium in hexane (66.0 mL, 165 mmol, 1.1 equiv). The resulting milky suspension was stirred at −78° C. for 30 min. Methyl chloroformate (17.6 mL, 225 mmol, 1.5 equiv) was then added. The reaction mixture became a clear solution. The cooling bath was then removed, and the reaction mixture was allowed to warm to room temperature and stirred at room temperature for 1 h. The reaction mixture became a suspension again. When TLC (5% EtOAc/hexane, KMnO4 stain) showed the reaction was deemed complete, the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) and extracted with diethyl ether (Et2O, 2×200 mL). The combined organic layers were washed with saturated aqueous NaCl solution, dried over magnesium sulfate (MgSO4), filtered and concentrated under the reduced pressure. The residue was distilled under vacuum (99-101° C./16 mbar) to afford methyl 3-cyclopentylpropiolate (18, 21.856 g, 22.83 g theoretical, 96% yield) as a colorless oil. For 18: 1H NMR (CDCl3, 400 MHz) δ ppm 3.74 (s, 3H), 2.73 (m, 1H), 1.95 (m, 2H), 1.72 (m, 4H), 1.57 (m, 2H). The cooling bath was then removed to warm to room temperature stirred at room temperature for 1 h the reaction mixture was quenched with saturated aqueous NH4Cl solution (150 mL) extracted with diethyl ether (Et2O, 2×200 mL) The combined organic layers were washed with saturated aqueous NaCl solution dried over magnesium sulfate (MgSO4) filtered concentrated under the reduced pressure The residue was distilled under vacuum (99-101° C./16 mbar)