Tetrabutylammonium Fluoride → tert-Butyl(3S)-3-hydroxymethyl-4-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylate

Tert-butyl (3S)-3-{[tert-butyl(dimethyl) silyloxy]methyl}-4-methyl-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylate (3.72 g, 8.31 mmol) was dissolved in tetrahydrofuran (70 mL), and tetrabutylammonium fluoride (12.5 mL, 1.0 mol/l solution in tetrahydrofuran, 12.5 mmol) was added dropwise in an ice bath. The mixture was stirred at the same temperature for 1 hour. After concentrating the mixture, saturated aqueous solution of ammonium chloride (200 mL) was added, and the mixture was extracted with ethyl acetate (200 mL×2). The organic layer was washed with saturated aqueous solution of sodium chloride (100 mL), and dried with anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure. The concentrate was purified by silica gel column chromatography (elusion by hexane:ethyl acetate=3:1→1:2) to obtain 1.87 g (67%) of the title compound as a white solid.

1. concentrationAfter concentrating the mixture, saturated aqueous solution of ammonium chloride (200 mL)
2. additionwas added
3. extractionthe mixture was extracted with ethyl acetate (200 mL×2)
4. washThe organic layer was washed with saturated aqueous solution of sodium chloride (100 mL)
5. dry with materialdried with anhydrous sodium sulfate
6. filtrationAfter filtration
7. concentrationthe filtrate was concentrated under reduced pressure
8. customThe concentrate was purified by silica gel column chromatography (elusion by hexane:ethyl acetate=3:1→1:2)

ORD-Eintrag

ord-01ae33b9a02a469094fa91f5b2689538

Quelldatensatz

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08211910B2