反应详情

To a solution of (R)-2-(((benzyloxy)carbonyl)amino)-5-(tert-butoxy)-5-oxopentanoic acid (1.41 g, 4.18 mmol) and MeI (2.091 mL, 33.4 mmol) in THF (12.66 ml) at 0° C. was slowly added NaH (0.501 g, 12.54 mmol) and the suspension was allowed to stir while warming up to room temperature for 24 hours. The reaction mixture was cooled to 0° C. before 10 mL of EtOAc were added along with 5 mL of water to quench the excess of NaH. The crude product was partitioned between a saturated NaHCO3 aqueous solution and Et2O. The two phases were separated and the organic phase was washed with a saturated NaHCO3 solution and both aqueous extracts were combined. The aqueous solution was brought to pH 3 using a 6N HCl aqueous solution. The aqueous phase was extracted with EtOAc, the organic extracts were combined and dried over anhydrous sodium sulfate. After filtration and concentration, (R)-2-(((benzyloxy)carbonyl)(methyl)amino)-5-(tert-butoxy)-5-oxopentanoic acid was obtained as a yellow oil, 1.4 g (78%). LCMS showed the m/z of desired product, (M+Na)+ 374.

1. customat 0° C.
2. customto quench the excess of NaH
3. customThe crude product was partitioned between a saturated NaHCO3 aqueous solution and Et2O
4. customThe two phases were separated
5. washthe organic phase was washed with a saturated NaHCO3 solution
6. extractionThe aqueous phase was extracted with EtOAc
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationAfter filtration and concentration