cyclopentanethiol

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:0.00; pressure:0.00; stir:

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

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of diazo-(3,4-dichloro-phenyl)-acetic acid methyl ester (Example 1; 193 mg, 0.79 mmol) in dichloromethane (10 mL) at 25° C. was treated with cyclopentyl mercaptan (0.21 mL, 1.97 mmol) followed by rhodium (II) acetate dimer (9 mg, 0.020 mmol) and the solution was stirred at 25° C. for 1 h. During this time no evolution of gas was detected, and examination of the black solution by thin layer chromatography indicated that only starting material was present. The reaction was heated to reflux and a second portion of rhodium (II) acetate dimer (10 mg, 0.024 mmol) was added and as the mixture was stirred at reflux for 110 min, a vigorous evolution of gas was observed. The reaction mixture was diluted with dichloromethane (10 mL), then was poured into water (15 mL) and extracted with dichloromethane (3×10 mL). The combined organic extracts were dried over sodium sulfate, filtered and evaporated under reduced pressure. The residual oil was purified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 95/5 hexanes/ethyl acetate) to furnish rac-cyclopentylsulfanyl-(3,4-dichloro-phenyl)-acetic acid methyl ester (148 mg, 59% yield) as a colorless oil: EI-HRMS m/e calcd for C14H16Cl2SO2(M+) 318.0248, found 318.0244. The reaction was heated to reflux was stirred at reflux for 110 min extracted with dichloromethane (3×10 mL) The combined organic extracts were dried over sodium sulfate filtered evaporated under reduced pressure The residual oil was purified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 95/5 hexanes/ethyl acetate)

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

Procedure: To a solution of 5 g (48.7 mmol) of cyclopentyl thiol in ethanol (50 mL) are added 2.7 g (48.75 mmol) of KOH pellets, followed by 9.5 g (48.7 mmol) of ethyl α-bromoisobutyrate. The reaction is heated to reflux for 2 h and then cooled to room temperature. The solid (KBr) is separated by filtration and rinsed with ethanol (20 mL). The filtrate is concentrated under reduced pressure and the residue dissolved in DCM (50 mL). The organic layer is washed with saturated aqueous NaHCO3 solution (50 mL). The aqueous washes are back-extracted with DCM (10 mL). The combined organics are washed with brine, dried over Na2SO4. Filtration and concentration under reduced pressure affords 8.1 g of 2-cyclopentylsulfanyl-2-methyl-propionic acid ethyl ester. Yield: 77%, ES-MS: m/z 217 [M+H] The reaction is heated to reflux for 2 h The solid (KBr) is separated by filtration rinsed with ethanol (20 mL) The filtrate is concentrated under reduced pressure the residue dissolved in DCM (50 mL) The organic layer is washed with saturated aqueous NaHCO3 solution (50 mL) The aqueous washes are back-extracted with DCM (10 mL) The combined organics are washed with brine dried over Na2SO4 Filtration and concentration under reduced pressure

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

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

Procedure: Cyclopentylmercaptan (ca 1.5g, 0.015M) was added to a solution of sodium hydroxide (0.6g, 0.015M) in water (3 ml). Dioxan (45 ml) was added, followed by chloroacetylferrocene (3.9g, 0.015M), and the mixture was heated at 100° for 2 hours with stirring. On cooling, water was added to the reaction mixture which was then extracted with chloroform. The organic layer was washed with dilute sodium hydroxide and water before it was dried over anhydrous magnesium sulphate and evaporated to an oil on a rotary evaporator. The product was isolated after column chromatography on silica gel using gradient elution with 1-21/2% (v/v) ethyl acetate in petroleum ether (60-80). Orange needles (0.40g) of the title compound were obtained mp = 78°-9°. the mixture was heated at 100° for 2 hours On cooling was then extracted with chloroform The organic layer was washed with dilute sodium hydroxide and water before it was dried over anhydrous magnesium sulphate evaporated to an oil on a rotary evaporator The product was isolated after column chromatography on silica gel using gradient elution with 1-21/2% (v/v) ethyl acetate in petroleum ether (60-80)

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

Procedure: Cyclopentylmercaptan (ca 1.5g, 0.015M) was added to a solution of sodium hydroxide (0.6g, 0.015M) in water (3 ml). Dioxan (45 ml) was added, followed by chloroacetylferrocene (3.9g, 0.015M), and the mixture was heated at 100° for 2 hours with stirring. On cooling, water was added to the reaction mixture which was then extracted with chloroform. The organic layer was washed with dilute sodium hydroxide and water before it was dried over anhydrous magnesium sulphate and evaporated to an oil on a rotary evaporator. The product was isolated after column chromatography on silica gel using gradient elution with 1-21/2% (v/v) ethyl acetate in petroleum ether (60-80). Orange needles (0.40g) of the title compound were obtained mp = 78°-9°. the mixture was heated at 100° for 2 hours On cooling was then extracted with chloroform The organic layer was washed with dilute sodium hydroxide and water before it was dried over anhydrous magnesium sulphate evaporated to an oil on a rotary evaporator The product was isolated after column chromatography on silica gel using gradient elution with 1-21/2% (v/v) ethyl acetate in petroleum ether (60-80)

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

Procedure: This compound was prepared as described in Example 108: 3 g (0.0083 mol) of product of Example 103, 1.02 g (0.01 mol) of cyclopentylmercaptan and 0.36 g (0.009 mol) of 60NaH in 50 ml of dry THF were reacted affording 3.8 g of a red oil. Crude was purified by HPLC using 1ethyl acetate/cyclohexane as eluting solvent to give 2.5 g of a light yellow oil which gas chromatography showed to be 94% pure. This material was passed through a spinning plate preparative chromatograph in two different portions of 1.25 g each (eluting solvent: 40CH2Cl2 /cyclohexane) to give, after kugelrohr distillation at 105-125° C./106 Pa, 1.95 g (55%) of product as a clear oil; nD25 1.4831. This compound was prepared

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

Procedure: This compound was prepared as described in Example 108: 3 g (0.0083 mol) of product of Example 103, 1.02 g (0.01 mol) of cyclopentylmercaptan and 0.36 g (0.009 mol) of 60NaH in 50 ml of dry THF were reacted affording 3.8 g of a red oil. Crude was purified by HPLC using 1ethyl acetate/cyclohexane as eluting solvent to give 2.5 g of a light yellow oil which gas chromatography showed to be 94% pure. This material was passed through a spinning plate preparative chromatograph in two different portions of 1.25 g each (eluting solvent: 40CH2Cl2 /cyclohexane) to give, after kugelrohr distillation at 105-125° C./106 Pa, 1.95 g (55%) of product as a clear oil; nD25 1.4831. This compound was prepared