反应详情

To a solution of benzyl-(3R,5S)-3-[(tert-butoxycarbonyl)amino]-5-methyl-4-oxopiperidine-1-carboxylate (1.61 g, 4.44 mmol) in THF (30 mL) at −78° C. a solution of methylmagnesium bromide in ether (3.0 M, 4.4 mL, 13 mmol) was added. The reaction was then quenched by adding aq. NH4Cl, and the resulting mixture was extracted with EtOAc. The combined organic extracts were dried and concentrated under reduced pressure. The residue was purified by silica gel chromatography eluting with 20-80% EtOAc in hexanes to give a mixture of the two diastereoisomers of the sub-title compound as a colorless oil (0.95 g, 56%). LCMS calc. for C20H30N2NaO5 (M+Na)+ m/z=401.2. found 401.0.40% of unreacted starting material was also isolated.

1. customThe reaction was then quenched
2. additionby adding aq. NH4Cl
3. extractionthe resulting mixture was extracted with EtOAc
4. customThe combined organic extracts were dried
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by silica gel chromatography
7. washeluting with 20-80% EtOAc in hexanes
8. customto give