4-Oxo-Tetrahydro-Furan-3-Carboxylic Acid Tert-Butyl Ester

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: The product of Step A, tert-butyl 4-oxotetrahydrofuran-3-carboxylate (0.95 g, 5.10 mmol) was placed in isopropylalcohol (14 mL) at 0-5° C., NaBH4 (77 mg, 2.04 mmol) was added, and stirred for 2 h. NaBH (77 mg, 2.04 mmol) was added again, and stirred at rt for 1 h, NaBH4 (39 mg, 1.02 mmol) was added, and stirred for 30 min. The reaction mixture was treated with Et2O to dilute, washed with brine, and extracted with Et2O twice. The organic layer was collected, extracted with a NaHCO3 aqueous solution, dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by column chromatography (eluent, EtOAc/Hex=1/3) to give the title compound (0.83 g, 86.56%). stirred at rt for 1 h stirred for 30 min to dilute washed with brine extracted with Et2O twice The organic layer was collected extracted with a NaHCO3 aqueous solution dried over MgSO4 filtered concentrated in vacuo The residue was purified by column chromatography (eluent, EtOAc/Hex=1/3)