反应详情

To a solution of oxalyl chloride (13.17 mL, 0.150 mol) in CH2Cl2 (250 mL) at −78° C. was added DMSO (14.23 mL, 0.201 mol) dropwise. The reaction was aged for 20 min at −78° C., then ±Benzyl trans-5-hydroxy-2-methylpiperidine-1-carboxylate (25.0 g, 0.100 mol) was added dropwise over 10 min and aged for an additional 10 min before triethylamine (41.9 mL, 0.301 mol) was added dropwise over 5 min at −78° C. The reaction was warmed to room temperature, then quenched with addition of half-saturated, aqueous NaHCO3 and additional CH2Cl2. The layers were separated, and the organics were dried with MgSO4 and concentrated. The crude material was purified by silica gel gradient chromatography (0-50% ethyl acetate in hexanes), providing ±benzyl 2-methyl-5-oxopiperidine-1-carboxylate.

1. additionwas added dropwise over 5 min at −78° C
2. customquenched with addition of half-saturated, aqueous NaHCO3 and additional CH2Cl2
3. customThe layers were separated
4. dry with materialthe organics were dried with MgSO4
5. concentrationconcentrated
6. customThe crude material was purified by silica gel gradient chromatography (0-50% ethyl acetate in hexanes)