benzyl 2-[(3S)-3-amino-2-oxopiperidin-1-yl]acetate;hydrochloride

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

Procedure: To a solution of compound 40 (4.00 g, 0.0110 mole) in 10 mL of ethyl acetate at room temperature was added 5N HCl in ethyl acetate (50 mL, freshly prepared, 0.25 mole) in one portion. The solution was stirred for 3 hrs, solvent was evaporated, CH2Cl2 was added and the solvents were reevaporated. The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford 3.37 g (~Quantitative crude yield) of product 41 as a colorless foam. TLC (silica gel; CH2Cl2, methanol, conc. NH4OH: 27:3:1): Rf=0.32. freshly prepared solvent was evaporated CH2Cl2 was added the solvents were reevaporated The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford

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

Procedure: To a mixture of 41 (1.50 g, 5.02 mmol) and phenylacetaldehyde (0.724 g, 6.03 mmol) in 35 mL of 1, 2-dichloroethane was added triethylamine (2.03 g, 21.1 mmol, 2.80 mL). After stirring at ambient temperature for 10 min, sodium triacetoxyborohydride (1.49 g, 7.03 mmol) was added rapidly over a 5 min period. The reaction mixture was stirred at room temperature for 15 hrs and quenched with 30 mL of water. The mixture was diluted with 50 mL of CH2Cl2 and the organic phase was separated, washed with 30 mL portions of saturated NaHCO3, water, brine, dried over MgSO4, filtered, and evaporated. The residue was purified by flash chromatography on silica gel eluting with CH2C12, ethanol: 95, 5 to afford 1.21 g (66% yield) of product 42 as a pale yellow oil; TLC (silica gel; CH2Cl2, ethanol: 9, 1): Rf=0.4 The reaction mixture was stirred at room temperature for 15 hrs quenched with 30 mL of water The mixture was diluted with 50 mL of CH2Cl2 the organic phase was separated washed with 30 mL portions of saturated NaHCO3, water, brine dried over MgSO4 filtered evaporated The residue was purified by flash chromatography on silica gel eluting with CH2C12, ethanol

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

Procedure: To a solution of compound 40 (4.00 g, 0.0110 mole) in 10 mL of ethyl acetate at room temperature was added 5N HCl in 5 ethyl acetate (50 mL, freshly prepared, 0.25 mole) in one portion. The solution was stirred for 3 hrs, solvent was evaporated, CH2Cl2 was added and the solvents were reevaporated. The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford 3.37 g (~Quantitative crude yield) of product 41 as a colorless foam. TLC (silica gel; CH2Cl2, methanol, conc. NH4OH: 27:3:1): Rf=0.32. freshly prepared solvent was evaporated CH2Cl2 was added the solvents were reevaporated The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford

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

Procedure: To a solution of the compound of Example 38 (4.00 g, 0.0110 mole) in 10 mL of ethyl acetate at room temperature was added 5N HCl in ethyl acetate (50 mL, freshly prepared, 0.25 mole) in one portion. The solution was stirred for 3 hrs, solvent was evaporated, CH2Cl2 was added and the solvents were reevaporated. The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford 3.37 g (~Quantitative crude yield) of product as a colorless foam. TLC (silica gel; CH2Cl2, methanol, conc. NH4OH: 27:3:1): Rf=0.32. freshly prepared solvent was evaporated CH2Cl2 was added the solvents were reevaporated The residue was pumped at <1 mm Hg on a vacuum pump for 24 hours to afford 3.37 g (~Quantitative crude yield) of product as a colorless foam