tert-butyl 3-hydroxy-2-methylpiperidine-1-carboxylate

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

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of oxalyl chloride (4.06 mL, 46.5 mmol) in 50 mL of dichloromethane was cooled to −78° C. and 4.95 mL (69.8 mmol) of dimethyl sulfoxide was added slowly and the mixture was stirred at −78° C. for 10 min. Then a solution of 5.00 g (23.3 mmol) of tert-butyl 3-hydroxy-2-methylpiperidine-1-carboxylate (Step B) in 5 mL of dichloromethane was added dropwise to above mixture. The mixture was stirred at −78° C. for 20 min, then 40.5 mL (232 mmol) of N,N-diisopropylethylamine was added to the mixture. The reaction was warmed to ambient temperature and continued to stir at ambient temperature for 1 h. The mixture was partitioned between dichloromethane and water. The aqueous phase was extracted with three potions of dichloromethane. The combined organic layers were washed with brine, dried over magnesium sulfate, and concentrated. Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane) gave the title compound. LC/MS 214 (M+1). The mixture was stirred at −78° C. for 20 min The reaction was warmed to ambient temperature to stir at ambient temperature for 1 h The mixture was partitioned between dichloromethane and water The aqueous phase was extracted with three potions of dichloromethane The combined organic layers were washed with brine dried over magnesium sulfate concentrated Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane)

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of oxalyl chloride (4.06 mL, 46.5 mmol) in 50 mL of dichloromethane was cooled to −78° C. and 4.95 mL (69.8 mmol) of dimethyl sulfoxide was added slowly and the mixture was stirred at −78° C. for 10 min. Then a solution of 5.00 g (23.3 mmol) of tert-butyl 3-hydroxy-2-methylpiperidine-1-carboxylate (Step B) in 5 mL of dichloromethane was added dropwise to above mixture. The mixture was stirred at −78° C. for 20 min, then 40.5 mL (232 mmol) of N,N-diisopropylethylamine was added to the mixture. The reaction was warmed to ambient temperature and continued to stir at ambient temperature for 1 h. The mixture was partitioned between dichloromethane and water. The aqueous phase was extracted with three potions of dichloromethane. The combined organic layers were washed with brine, dried over magnesium sulfate, and concentrated. Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane) gave the title compound. LC/MS 214 (M+1). The mixture was stirred at −78° C. for 20 min The reaction was warmed to ambient temperature to stir at ambient temperature for 1 h The mixture was partitioned between dichloromethane and water The aqueous phase was extracted with three potions of dichloromethane The combined organic layers were washed with brine dried over magnesium sulfate concentrated Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane)

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

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of oxalyl chloride (4.06 mL, 46.5 mmol) in 50 mL of dichloromethane was cooled to −78° C. and 4.95 mL (69.8 mmol) of dimethyl sulfoxide was added slowly and the mixture was stirred at −78° C. for 10 min. Then a solution of 5.00 g (23.3 mmol) of tert-butyl 3-hydroxy-2-methylpiperidine-1-carboxylate (Step B) in 5 mL of dichloromethane was added dropwise to above mixture. The mixture was stirred at −78° C. for 20 min, then 40.5 mL (232 mmol) of N,N-diisopropylethylamine was added to the mixture. The reaction was warmed to ambient temperature and continued to stir at ambient temperature for 1 h. The mixture was partitioned between dichloromethane and water. The aqueous phase was extracted with three potions of dichloromethane. The combined organic layers were washed with brine, dried over magnesium sulfate, and concentrated. Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane) gave the title compound. LC/MS 214 (M+1). The mixture was stirred at −78° C. for 20 min The reaction was warmed to ambient temperature to stir at ambient temperature for 1 h The mixture was partitioned between dichloromethane and water The aqueous phase was extracted with three potions of dichloromethane The combined organic layers were washed with brine dried over magnesium sulfate concentrated Purification by flash chromatography on a Biotage®D system (silica gel, eluting with 10% ethyl acetate/hexane to 30% ethyl acetate/hexane)

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