ditert-butyl 2,3-dihydroxybutanedioate

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

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

Procedure: 50% NaOH solution (1.2 g-30 mmol) is added in the course of ½ hour to a solution of 3,4-bis(phenylsulphonyl)-1,2,5-oxadiazole 2-oxide (7 g-19 mmol) and di-tert-butyl tartrate (5 g-19 mmol) in 100 ml of anhydrous THF. After stirring for 5 hours, the solvent is evaporated off to dryness and the residue is taken up in water and ethyl acetate. The organic fraction is dried with Na2SO4 and evaporated to dryness and subsequently purified by flash chromatography, using a (98:2) dichloromethane/ethanol mixture as eluant, to yield the expected product in the form of a colourless oil. the solvent is evaporated off to dryness The organic fraction is dried with Na2SO4 evaporated to dryness subsequently purified by flash chromatography

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

Procedure: 50% NaOH solution (1.2 g-30 mmol) is added in the course of ½ hour to a solution of 3,4-bis(phenylsulphonyl)-1,2,5-oxadiazole 2-oxide (7 g-19 mmol) and di-tert-butyl tartrate (5 g-19 mmol) in 100 ml of anhydrous THF. After stirring for 5 hours, the solvent is evaporated off to dryness and the residue is taken up in water and ethyl acetate. The organic fraction is dried with Na2SO4 and evaporated to dryness and subsequently purified by flash chromatography, using a (98:2) dichloromethane/ethanol mixture as eluant, to yield the expected product in the form of a colourless oil. the solvent is evaporated off to dryness The organic fraction is dried with Na2SO4 evaporated to dryness subsequently purified by flash chromatography

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

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

Procedure: (Step 1) To di-tert-butyl tartrate (182 mg, 0.692 mmol), dichloromethane (1.73 mL), triethylamine (0.145 mL, 1.04 mmol), and diethylchlorophosphoric acid (0.050 mL, 0.346 mmol) were added, and the resulting mixture was stirred at room temperature for 20 hours. To the reaction mixture, water was added, and the resulting mixture was extracted with chloroform. The organic layer was dried, over sodium sulfate, and the solvent was evaporated under reduced pressure. The resulting residue was purified by silica, gel column chromatography (ethyl acetate/n-hexane=5/95 to 30/70), whereby di-tert-butyl (2R,3R)-2-(diethoxyphosphoryloxy)-3-hydroxysuccinate (46 mg, 33%) was obtained. the resulting mixture was extracted with chloroform The organic layer was dried, over sodium sulfate the solvent was evaporated under reduced pressure The resulting residue was purified by silica, gel column chromatography (ethyl acetate/n-hexane=5/95 to 30/70)

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

Procedure: 50% NaOH solution (1.2 g-30 mmol) is added in the course of ½ hour to a solution of 3,4-bis(phenylsulphonyl)-1,2,5-oxadiazole 2-oxide (7 g-19 mmol) and di-tert-butyl tartrate (5 g-19 mmol) in 100 ml of anhydrous THF. After stirring for 5 hours, the solvent is evaporated off to dryness and the residue is taken up in water and ethyl acetate. The organic fraction is dried with Na2SO4 and evaporated to dryness and subsequently purified by flash chromatography, using a (98:2) dichloromethane/ethanol mixture as eluant, to yield the expected product in the form of a colourless oil. the solvent is evaporated off to dryness The organic fraction is dried with Na2SO4 evaporated to dryness subsequently purified by flash chromatography