methyl 3-oxothiane-2-carboxylate

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

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

Procedure: To a suspension of sodium (3.5 g, 0.15 mol) in dry toluene (300 mL) was added an excess of methanol (30 mL). After sodium was disappeared, the excess methanol was removed as the methanol-toluene azeotrope. When the distillation temperature had reached 105° C., Methyl 4-{[2-(methyloxy)-2-oxoethyl]thio}butanoate (28.3 g, 0.14 mol) in toluene (90 mL) was added over a period of ten mins. The methanol-toluene azeotrope was removed by distillation, after the distillation temperature rose to 106° C., the reaction mixture was cooled to room temperature. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL). The organic layer was removed and the aqueous layer was extracted with three 60 mL portions of ether and the combined organic layers were dried over Na2SO4. After removing the solvent, 23.4 g of crude product was obtained (Yield: 96%). the excess methanol was removed as the methanol-toluene azeotrope had reached 105° C. The methanol-toluene azeotrope was removed by distillation rose to 106° C. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL) The organic layer was removed the aqueous layer was extracted with three 60 mL portions of ether the combined organic layers were dried over Na2SO4 After removing the solvent

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

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

Procedure: To a suspension of sodium (3.5 g, 0.15 mol) in dry toluene (300 mL) was added an excess of methanol (30 mL). After sodium was disappeared, the excess methanol was removed as the methanol-toluene azeotrope. When the distillation temperature had reached 105° C., Methyl 4-{[2-(methyloxy)-2-oxoethyl]thio}butanoate (28.3 g, 0.14 mol) in toluene (90 mL) was added over a period of ten mins. The methanol-toluene azeotrope was removed by distillation, after the distillation temperature rose to 106° C., the reaction mixture was cooled to room temperature. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL). The organic layer was removed and the aqueous layer was extracted with three 60 mL portions of ether and the combined organic layers were dried over Na2SO4. After removing the solvent, 23.4 g of crude product was obtained (Yield: 96%). the excess methanol was removed as the methanol-toluene azeotrope had reached 105° C. The methanol-toluene azeotrope was removed by distillation rose to 106° C. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL) The organic layer was removed the aqueous layer was extracted with three 60 mL portions of ether the combined organic layers were dried over Na2SO4 After removing the solvent

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

Procedure: To a suspension of sodium (3.5 g, 0.15 mol) in dry toluene (300 mL) was added an excess of methanol (30 mL). After sodium was disappeared, the excess methanol was removed as the methanol-toluene azeotrope. When the distillation temperature had reached 105° C., Methyl 4-{[2-(methyloxy)-2-oxoethyl]thio}butanoate (28.3 g, 0.14 mol) in toluene (90 mL) was added over a period of ten mins. The methanol-toluene azeotrope was removed by distillation, after the distillation temperature rose to 106° C., the reaction mixture was cooled to room temperature. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL). The organic layer was removed and the aqueous layer was extracted with three 60 mL portions of ether and the combined organic layers were dried over Na2SO4. After removing the solvent, 23.4 g of crude product was obtained (Yield: 96%). the excess methanol was removed as the methanol-toluene azeotrope had reached 105° C. The methanol-toluene azeotrope was removed by distillation rose to 106° C. The reaction mixture was poured into a mixture of ice (100 g) and 12N HCl (20 mL) The organic layer was removed the aqueous layer was extracted with three 60 mL portions of ether the combined organic layers were dried over Na2SO4 After removing the solvent

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

Procedure: A solution of 14.2 g. (0.06 mole) of 5-(3-methyl-2-octyl)resorcinol and 11.1 g. (0.063 mole) of methyl-3-oxo2,3,4,5-tetrahydro-6H-thiopyran-2-carboxylate in 90 ml. of absolute ethanol was cooled in an ice-salt bath and saturated with anhydrous hydrogen chloride. After standing for 2 days at room temperature, the ethanol was removed on a rotary evaporator. The residue was dissolved in ether, washed with sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the solvent gave 28.0 g. of residue which was chromatographed using Florisil (60-100 mesh) and graded methanol/chloroform solvent mixtures. A total of 10 g. of crude solid was obtained from the 1% methanol/chloroform fractions. The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g. (40%) colorless crystals, m.p. 131°-133°. The proposed structure was confirmed by IR and nmr. the ethanol was removed on a rotary evaporator The residue was dissolved in ether washed with sodium bicarbonate solution dried over sodium sulfate Evaporation of the solvent gave 28.0 g of residue which was chromatographed of crude solid was obtained from the 1% methanol/chloroform fractions The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g

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

Procedure: A solution of 14.2 g. (0.06 mole) of 5-(3-methyl-2-octyl)resorcinol and 11.1 g. (0.063 mole) of methyl-3-oxo2,3,4,5-tetrahydro-6H-thiopyran-2-carboxylate in 90 ml. of absolute ethanol was cooled in an ice-salt bath and saturated with anhydrous hydrogen chloride. After standing for 2 days at room temperature, the ethanol was removed on a rotary evaporator. The residue was dissolved in ether, washed with sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the solvent gave 28.0 g. of residue which was chromatographed using Florisil (60-100 mesh) and graded methanol/chloroform solvent mixtures. A total of 10 g. of crude solid was obtained from the 1% methanol/chloroform fractions. The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g. (40%) colorless crystals, m.p. 131°-133°. The proposed structure was confirmed by IR and nmr. the ethanol was removed on a rotary evaporator The residue was dissolved in ether washed with sodium bicarbonate solution dried over sodium sulfate Evaporation of the solvent gave 28.0 g of residue which was chromatographed of crude solid was obtained from the 1% methanol/chloroform fractions The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g

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

Procedure: A solution of 14.2 g. (0.06 mole) of 5-(3-methyl-2-octyl)resorcinol and 11.1 g. (0.063 mole) of methyl-3-oxo2,3,4,5-tetrahydro-6H-thiopyran-2-carboxylate in 90 ml. of absolute ethanol was cooled in an ice-salt bath and saturated with anhydrous hydrogen chloride. After standing for 2 days at room temperature, the ethanol was removed on a rotary evaporator. The residue was dissolved in ether, washed with sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the solvent gave 28.0 g. of residue which was chromatographed using Florisil (60-100 mesh) and graded methanol/chloroform solvent mixtures. A total of 10 g. of crude solid was obtained from the 1% methanol/chloroform fractions. The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g. (40%) colorless crystals, m.p. 131°-133°. The proposed structure was confirmed by IR and nmr. the ethanol was removed on a rotary evaporator The residue was dissolved in ether washed with sodium bicarbonate solution dried over sodium sulfate Evaporation of the solvent gave 28.0 g of residue which was chromatographed of crude solid was obtained from the 1% methanol/chloroform fractions The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g

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

Procedure: Potassium t-butoxide (1 M in THF) (56.0 mL, 56.0 mmol) was added to an ice cold solution of methyl 4-[(2-methoxy-2-oxoethyl)sulfanyl]butanoate (10.5 g, 50.9 mmol) from (361a), in diethyl ether (200 mL) under nitrogen atmosphere. The reaction was allowed to warm to room temperature and stirred for 2 h. The reaction was partitioned between ethyl ether and water. The organic layer was washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate and concentrated to give methyl 3-oxotetrahydro-2H-thiopyran-2-carboxylate (8.5 g, 82%) as a yellow oil. The reaction was partitioned between ethyl ether and water The organic layer was washed with saturated aqueous sodium bicarbonate dried over magnesium sulfate concentrated

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

Procedure: Potassium t-butoxide (1 M in THF) (56.0 mL, 56.0 mmol) was added to an ice cold solution of methyl 4-[(2-methoxy-2-oxoethyl)sulfanyl]butanoate (10.5 g, 50.9 mmol) from (361a), in diethyl ether (200 mL) under nitrogen atmosphere. The reaction was allowed to warm to room temperature and stirred for 2 h. The reaction was partitioned between ethyl ether and water. The organic layer was washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate and concentrated to give methyl 3-oxotetrahydro-2H-thiopyran-2-carboxylate (8.5 g, 82%) as a yellow oil. The reaction was partitioned between ethyl ether and water The organic layer was washed with saturated aqueous sodium bicarbonate dried over magnesium sulfate concentrated

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

Procedure: A solution of 14.2 g. (0.06 mole) of 5-(3-methyl-2-octyl)resorcinol and 11.1 g. (0.063 mole) of methyl-3-oxo-2,3,4,5-tetrahydro-6H-thiopyran-2-carboxylate in 90 ml. of absolute ethanol was cooled in an ice-salt bath and saturated with anhydrous hydrogen chloride. After standing for 2 days at room temperature, the ethanol was removed on a rotary evaporator. The residue was dissolved in ether, washed with sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the solvent gave 28.0 g. of residue which was chromatographed using magnesium silicate (60-100 mesh) and graded methanol/chloroform solvent mixtures. A total of 10 g. of crude solid was obtained frm the 1% methanol/chloroform fractions. The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g. 40%) of colorless crystals, m.p. 131°-133°C. The proposed structure was confirmed by infrared and nuclear magnetic resonance spectra. the ethanol was removed on a rotary evaporator The residue was dissolved in ether washed with sodium bicarbonate solution dried over sodium sulfate Evaporation of the solvent gave 28.0 g of residue which was chromatographed of crude solid was obtained frm the 1% methanol/chloroform fractions The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g

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

Procedure: A solution of 14.2 g. (0.06 mole) of 5-(3-methyl-2-octyl)resorcinol and 11.1 g. (0.063 mole) of methyl 3-oxo-2,3,4,5-tetrahydro-6H-thiopyran-2-carboxylate in 90 ml. of absolute ethanol was cooled in an ice-salt bath and saturated with anhydrous hydrogen chloride. After standing for 2 days at room temperature, the ethanol was removed on a rotary evaporator. The residue was dissolved in ether, washed with sodium bicarbonate solution and dried over sodium sulfate. Evaporation of the solvent gave 28.0 g. of residue which was chromatographed using activated magnesium silicate (60-100 mesh) and graded methanol/chloroform solvent mixtures. A total of 10 g. of crude solid was obtained from the 1% methanol/chloroform fractions. The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g. (40%) colorless crystals, m.p. 131°-133°C. The proposed structure was confirmed by IR and NMR spectra. the ethanol was removed on a rotary evaporator The residue was dissolved in ether washed with sodium bicarbonate solution dried over sodium sulfate Evaporation of the solvent gave 28.0 g of residue which was chromatographed of crude solid was obtained from the 1% methanol/chloroform fractions The material was recrystallized twice from ethyl acetate/hexane to give 8.5 g