methyl 2-hydroxy-4-methylsulfanylbutanoate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of DL, 2-hydroxy-4-methylmercaptobutyric acid calcium salt (2.2 g) in 0.5M HCl (50 mL) was saturated with sodium chloride, extracted exhaustively with EtOAc, which was dried (MgSO4), filtered and concentrated. The residue was dissolved in methanol (10 mL) and trimethylsilyldiazomethane (2M in hexane) was added until the yellow color persisted for 30 min. The reaction was quenched by addition of glacial acetic acid and concentrated. The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane to give the title compound as a light yellow oil (1.37 g). extracted exhaustively with EtOAc, which was dried (MgSO4) filtered concentrated The residue was dissolved in methanol (10 mL) trimethylsilyldiazomethane (2M in hexane) was added until the yellow color The reaction was quenched by addition of glacial acetic acid concentrated The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Commercial calcium 2-hydroxy-4-(methylthio)butyrate (20 g, 0.12 mol) was suspended in 250 ml CH2Cl2. CH3OH (15 ml, 0.36 mol) was added and the mixture cooled to 10° C., at which point H2SO4 (3.7 ml, 0.07 mol) was added. An obvious physical change in the slurry was noted. The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction was nearly complete. As a matter of convenience, the reaction mixture was stirred 64 hours at room temperature, at which time insoluble byproducts were removed by filtration. The filtrate was washed with 150 ml each of saturated NaHCO3 and brine, dried (MgSO4) and stripped to yield title product as an oil; tlc Rf 0.8 (ethyl acetate)0.25 (3:1 hexane:ethyl acetate). was added The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction were removed by filtration The filtrate was washed with 150 ml each of saturated NaHCO3 and brine dried (MgSO4)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of DL, 2-hydroxy-4-methylmercaptobutyric acid calcium salt (2.2 g) in 0.5M HCl (50 mL) was saturated with sodium chloride, extracted exhaustively with EtOAc, which was dried (MgSO4), filtered and concentrated. The residue was dissolved in methanol (10 mL) and trimethylsilyldiazomethane (2M in hexane) was added until the yellow color persisted for 30 min. The reaction was quenched by addition of glacial acetic acid and concentrated. The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane to give the title compound as a light yellow oil (1.37 g). extracted exhaustively with EtOAc, which was dried (MgSO4) filtered concentrated The residue was dissolved in methanol (10 mL) trimethylsilyldiazomethane (2M in hexane) was added until the yellow color The reaction was quenched by addition of glacial acetic acid concentrated The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of DL, 2-hydroxy-4-methylmercaptobutyric acid calcium salt (2.2 g) in 0.5M HCl (50 mL) was saturated with sodium chloride, extracted exhaustively with EtOAc, which was dried (MgSO4), filtered and concentrated. The residue was dissolved in methanol (10 mL) and trimethylsilyldiazomethane (2M in hexane) was added until the yellow color persisted for 30 min. The reaction was quenched by addition of glacial acetic acid and concentrated. The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane to give the title compound as a light yellow oil (1.37 g). extracted exhaustively with EtOAc, which was dried (MgSO4) filtered concentrated The residue was dissolved in methanol (10 mL) trimethylsilyldiazomethane (2M in hexane) was added until the yellow color The reaction was quenched by addition of glacial acetic acid concentrated The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Commercial calcium 2-hydroxy-4-(methylthio)-butyrate (20 g, 0.12 mol) was suspended in 250 ml CH2Cl2. CH3OH (15 ml, 0.36 mol) was added and the mixture cooled to 10° C., at which point H2SO4 (3.7 ml, 0.07 mol) was added. An obvious physical change in the slurry was noted. The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction was nearly complete. As a matter of convenience, the reaction mixture was stirred 64 hours at room temperature, at which time insoluble byproducts were removed by filtration. The filtrate was washed with 150 ml each of saturated NaHCO3 and brine, dried (MgSO4) and stripped to yield title product as an oil; tlc Rf 0.8 (ethyl acetate)0.25 (3:1 hexane:ethyl acetate). was added The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction were removed by filtration The filtrate was washed with 150 ml each of saturated NaHCO3 and brine dried (MgSO4)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Commercial calcium 2-hydroxy-4-(methylthio)-butyrate (20 g, 0.12 mol) was suspended in 250 ml CH2Cl2. CH3OH (15 ml, 0.36 mol) was added and the mixture cooled to 10° C., at which point H2SO4 (3.7 ml, 0.07 mol) was added. An obvious physical change in the slurry was noted. The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction was nearly complete. As a matter of convenience, the reaction mixture was stirred 64 hours at room temperature, at which time insoluble byproducts were removed by filtration. The filtrate was washed with 150 ml each of saturated NaHCO3 and brine, dried (MgSO4) and stripped to yield title product as an oil; tlc Rf 0.8 (ethyl acetate)0.25 (3:1 hexane:ethyl acetate). was added The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction were removed by filtration The filtrate was washed with 150 ml each of saturated NaHCO3 and brine dried (MgSO4)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Commercial calcium 2-hydroxy-4-(methylthio)butyrate (20 g, 0.12 mol) was suspended in 250 ml CH2Cl2. CH3OH (15 ml, 0.36 mol) was added and the mixture cooled to 10° C., at which point H2SO4 (3.7 ml, 0.07 mol) was added. An obvious physical change in the slurry was noted. The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction was nearly complete. As a matter of convenience, the reaction mixture was stirred 64 hours at room temperature, at which time insoluble byproducts were removed by filtration. The filtrate was washed with 150 ml each of saturated NaHCO3 and brine, dried (MgSO4) and stripped to yield title product as an oil; tlc Rf 0.8 (ethyl acetate)0.25 (3:1 hexane:ethyl acetate). was added The mixture was heated at reflux for 60 minutes, by which time tlc indicated reaction were removed by filtration The filtrate was washed with 150 ml each of saturated NaHCO3 and brine dried (MgSO4)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of DL, 2-hydroxy-4-methylmercaptobutyric acid calcium salt (2.2 g) in 0.5M HCl (50 mL) was saturated with sodium chloride, extracted exhaustively with EtOAc, which was dried (MgSO4), filtered and concentrated. The residue was dissolved in methanol (10 mL) and trimethylsilyldiazomethane (2M in hexane) was added until the yellow color persisted for 30 min. The reaction was quenched by addition of glacial acetic acid and concentrated. The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane to give the title compound as a light yellow oil (1.37 g). extracted exhaustively with EtOAc, which was dried (MgSO4) filtered concentrated The residue was dissolved in methanol (10 mL) trimethylsilyldiazomethane (2M in hexane) was added until the yellow color The reaction was quenched by addition of glacial acetic acid concentrated The residue was purified by silica gel chromatography eluting with 30% EtOAc/hexane