反应详情

To a solution of (S)-3-azido-4,4-dimethyldihydrofuran-2(3H)-one (5.52 g) in MeOH 910 mL) was added 10% Pd/C (0.379 g, 0.356 mmol) under N2. The reaction mixture was stirred under H2 at rt for 16 hrs. The reaction was filtered through diatomaceous earth (Celite®), washed with EtOAc and the filtrate was concentrated to yield a clear oil. To the above oil in DCM (10 mL) was added BOC2O (9.09 mL) and TEA (13.88 mL). The reaction mixture was stirred at rt for 16 hrs. The reaction mixture was diluted with EtOAc, washed with sat. NaHCO3, citric acid, water, sat. NaCl, dried over anhydrous Na2SO4, filtered and concentrated to yield an oil. The crude product was purified by silica gel chromatography (0-100% EtOAc in hexane) to yield (S)-tert-butyl 4,4-dimethyl-2-oxotetrahydrofuran-3-ylcarbamate (3.8 g) as a white solid. LC/MS (Cond. N-1): [M+Na]+ 252.06, RT=2.75 min. 1H NMR (400 MHz, CHLOROFORM-d) ppm 4.81-4.95 (1H, m), 4.38 (1H, d, J=7.78 Hz), 3.97-4.07 (2H, m), 1.47 (9H, s), 1.25 (3H, s), 1.01 (3H, s).

1. filtrationThe reaction was filtered through diatomaceous earth (Celite®)
2. washwashed with EtOAc
3. concentrationthe filtrate was concentrated
4. customto yield a clear oil
5. stirringThe reaction mixture was stirred at rt for 16 hrs
6. washwashed with sat. NaHCO3, citric acid, water, sat. NaCl
7. dry with materialdried over anhydrous Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customto yield an oil
11. customThe crude product was purified by silica gel chromatography (0-100% EtOAc in hexane)