Pyridine → 1-tert-butyl 2-methyl (2S)-4-oxopyrrolidine-1,2-dicarboxylate

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Reaction Steps

CrO3 (194 g, 1.94 mol) was added slowly with stirring over 30 min to a solution of pyridine (340 mL) in DCM (900 mL) at 0° C. The mixture was warmed to rt and (2S,4R)-1-tert-butyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate (56 g, 0.216 mol) in DCM (700 mL) was added. The reaction was stirred vigorously for 4 hs at rt. The formed dark solid was decanted and washed with DCM. The organic phases were washed with aq. NaHCO3, 10% aqueous critic acid, and brine, and dried over anhydrous Na2SO4. The solvent was removed in vacuo and purified by silica gel column chromatography (PE: EtOAc=50:1 to 10:1) to afford (S)-1-tert-butyl 2-methyl 4-oxopyrrolidine-1,2-dicarboxylate (42.6 g, 81%) as yellow oil.

Provenance & Evidence