tert-butyl 2-oxa-9-azaspiro[5.5]undecane-9-carboxylate

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: Acetyl chloride (1 mL) was added to stirred, cooled (0° C.) methanol (10 mL) and the mixture was stirred at 0° C. for 5 minutes. 1,1-Dimethylethyl 2-oxa-9-azaspiro[5.5]undecane-9-carboxylate (Description 138, 78 mg, 0.27 mmol) was added and the mixture was stirred at room temperature for 3 hours. The solvent was evaporated under reduced pressure, aqueous sodium carbonate (10%, 10 mL) was added and the mixture was extracted with dichloromethane (3×10 mL). The combined organic fractions were dried (Na2SO4) and the solvent was evaporated under reduced pressure to give the title compound (50 mg, 100%). m/z (ES+) 156 (M+1). the mixture was stirred at 0° C. for 5 minutes the mixture was stirred at room temperature for 3 hours The solvent was evaporated under reduced pressure, aqueous sodium carbonate (10%, 10 mL) was added the mixture was extracted with dichloromethane (3×10 mL) The combined organic fractions were dried (Na2SO4) the solvent was evaporated under reduced pressure

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

Procedure: Acetyl chloride (1 mL) was added to stirred, cooled (0° C.) methanol (10 mL) and the mixture was stirred at 0° C. for 5 minutes. 1,1-Dimethylethyl 2-oxa-9-azaspiro[5.5]undecane-9-carboxylate (Description 138, 78 mg, 0.27 mmol) was added and the mixture was stirred at room temperature for 3 hours. The solvent was evaporated under reduced pressure, aqueous sodium carbonate (10%, 10 mL) was added and the mixture was extracted with dichloromethane (3×10 mL). The combined organic fractions were dried (Na2SO4) and the solvent was evaporated under reduced pressure to give the title compound (50 mg, 100%). m/z (ES+) 156 (M+1). the mixture was stirred at 0° C. for 5 minutes the mixture was stirred at room temperature for 3 hours The solvent was evaporated under reduced pressure, aqueous sodium carbonate (10%, 10 mL) was added the mixture was extracted with dichloromethane (3×10 mL) The combined organic fractions were dried (Na2SO4) the solvent was evaporated under reduced pressure

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

Procedure: Diethyl diazenedicarboxylate (390 μL, 2.46 mmol) was added to a solution of 1,1-dimethylethyl 4-(hydroxymethyl)-4-(3-hydroxypropyl)-1-piperidinecarboxylate (Description 137, 560 mg, 2.05 mmol) and triphenylphosphine (646 mg, 2.46 mmol) in tetrahydrofuran (10 mL) and the mixture was stirred at room temperature for 24 hours. Further triphenylphosphine (646 mg, 2.46 mmol) and diethyl diazenedicarboxylate (390 μL, 2.46 mmol) were added and the mixture was stirred at room temperature for 24 hours. Methanol (5 mL) was added and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with isohexane/EtOAc (75:25), to give the title compound (78 mg, 15%). m/z (ES+) 256 (M+1). the mixture was stirred at room temperature for 24 hours the solvent was evaporated under reduced pressure The residue was purified by flash column chromatography on silica gel eluting with isohexane/EtOAc (75:25)

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

Procedure: Diethyl diazenedicarboxylate (390 μL, 2.46 mmol) was added to a solution of 1,1-dimethylethyl 4-(hydroxymethyl)-4-(3-hydroxypropyl)-1-piperidinecarboxylate (Description 137, 560 mg, 2.05 mmol) and triphenylphosphine (646 mg, 2.46 mmol) in tetrahydrofuran (10 mL) and the mixture was stirred at room temperature for 24 hours. Further triphenylphosphine (646 mg, 2.46 mmol) and diethyl diazenedicarboxylate (390 μL, 2.46 mmol) were added and the mixture was stirred at room temperature for 24 hours. Methanol (5 mL) was added and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with isohexane/EtOAc (75:25), to give the title compound (78 mg, 15%). m/z (ES+) 256 (M+1). the mixture was stirred at room temperature for 24 hours the solvent was evaporated under reduced pressure The residue was purified by flash column chromatography on silica gel eluting with isohexane/EtOAc (75:25)

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

Procedure: Diethyl diazenedicarboxylate (390 μL, 2.46 mmol) was added to a solution of 1,1-dimethylethyl 4-(hydroxymethyl)-4-(3-hydroxypropyl)-1-piperidinecarboxylate (Description 137, 560 mg, 2.05 mmol) and triphenylphosphine (646 mg, 2.46 mmol) in tetrahydrofuran (10 mL) and the mixture was stirred at room temperature for 24 hours. Further triphenylphosphine (646 mg, 2.46 mmol) and diethyl diazenedicarboxylate (390 μL, 2.46 mmol) were added and the mixture was stirred at room temperature for 24 hours. Methanol (5 mL) was added and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with isohexane/EtOAc (75:25), to give the title compound (78 mg, 15%). m/z (ES+) 256 (M+1). the mixture was stirred at room temperature for 24 hours the solvent was evaporated under reduced pressure The residue was purified by flash column chromatography on silica gel eluting with isohexane/EtOAc (75:25)

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