4-hydroxy-2-[(2-methylpropan-2-yl)oxycarbonylamino]butanoic acid

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

Procedure: 6 g of the obtained N-t-butoxycarbonyl DL-homoserine was dissolved in 100 ml of methylene chloride, and 50 ml of a methylene chloride solution containing 6 g of diphenyldiazomethane was added dropwise thereto over an hour. After completion of the reaction, the reaction mixture was concentrated to a small volume, and petroleum ether was added thereto. The formed crystals were filtered off to obtain 8.6 g of N-t-butoxycarbonyl DL-homoserine benzhydryl ester. was added dropwise over an hour After completion of the reaction the reaction mixture was concentrated to a small volume, and petroleum ether was added The formed crystals were filtered off

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

Procedure: 6 g of the obtained N-t-butoxycarbonyl DL-homoserine was dissolved in 100 ml of methylene chloride, and 50 ml of a methylene chloride solution containing 6 g of diphenyldiazomethane was added dropwise thereto over an hour. After completion of the reaction, the reaction mixture was concentrated to a small volume, and petroleum ether was added thereto. The formed crystals were filtered off to obtain 8.6 g of N-t-butoxycarbonyl DL-homoserine benzhydryl ester. was added dropwise over an hour After completion of the reaction the reaction mixture was concentrated to a small volume, and petroleum ether was added The formed crystals were filtered off

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

Procedure: 6 g of the obtained N-t-butoxycarbonyl DL-homoserine was dissolved in 100 ml of methylene chloride, and 50 ml of a methylene chloride solution containing 6 g of diphenyldiazomethane was added dropwise thereto over an hour. After completion of the reaction, the reaction mixture was concentrated to a small volume, and petroleum ether was added thereto. The formed crystals were filtered off to obtain 8.6 g of N-t-butoxycarbonyl DL-homoserine benzhydryl ester. was added dropwise over an hour After completion of the reaction the reaction mixture was concentrated to a small volume, and petroleum ether was added The formed crystals were filtered off

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

Procedure: To a solution of homoserine bromohydrate (2 g; 16.78 mmol.) in H2O (20 ml), addition was made in succession of a 1 M NaOH solution (16.78 ml) and cesium carbonate (3.01 g; 9.23 mmol.). After stirring for 5 minutes, the solution was cooled in an ice/water bath. Dioxane (60 ml) and t-butyl pyrocarbonate were then added. The reaction mixture was kept under stirring in an ice-cold water bath for 1 hour and thereafter at room temperature for 5 hours. The solvent was subsequently evaporated under vacuum and the dry residue was directly used in the next step. the solution was cooled in an ice/water bath under stirring in an ice-cold water bath for 1 hour at room temperature for 5 hours The solvent was subsequently evaporated under vacuum

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

Procedure: 2-tert-Butoxycarbonylamino-4-hydroxy-butyric acid (0.79 g, 3.6 mmol) was dissolved in 15 ml methanol at room temperature and (trimethylsilyl)diazomethane (2M solution in hexane) was added till solution become yellow. The mixture was concentrated down to afford crude 2-tert-butoxycarbonylamino-4-hydroxy-butyric acid methyl ester. The mixture was concentrated down

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

Procedure: To a solution of homoserine bromohydrate (2 g ; 16.78 mmol.) in H2O (20 ml), addition was made in succession of a 1 M NaOH solution (16.78 ml) and cesium carbonate (3.01 g; 9.23 mmol.). After stirring for 5 minutes, the solution was cooled in an ice/water bath. Dioxane (60 ml) and t-butyl pyrocarbonate were then added. The reaction mixture was kept under stirring in an ice-cold water bath for 1 hour and thereafter at room temperature for 5 hours. The solvent was subsequently evaporated under vacuum and the dry residue was directly used in the next step. the solution was cooled in an ice/water bath under stirring in an ice-cold water bath for 1 hour at room temperature for 5 hours The solvent was subsequently evaporated under vacuum

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

Procedure: 2 g of homoserine (16.78 mmol) were dissolved in 20 ml of water and to the solution 16.78 ml of 1 M NaOH and 3.006 g of cesium carbonate (9.23 mmol) were added. After stirring for 5 minutes, the solution was cooled in an ice/water bath. 60 ml of dioxane and terbutyl pyrocarbonate were then added. The reaction mixture was kept under stirring in an ice-cold water bath for 1 hour and thereafter at room temperature for 5 hours. The solvent was subsequently removed under vacuum. The dry residue was directly used in the next step. were added the solution was cooled in an ice/water bath under stirring in an ice-cold water bath for 1 hour at room temperature for 5 hours The solvent was subsequently removed under vacuum