反应详情

A solution of tert-butyl (4R)-4-((1R,2S)-3-azido-1-{[tert-butyl(dimethyl)silyl]oxy}-2-cyclopropylpropyl)-2,2-dimethyl-1,3-oxazolidine-3-carboxylate (1.16 g, 2.55 mmol) in MeOH (5 mL) was cooled on an ice bath, then TFA (4.9 mL, 64 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred for 30 min. The volatile organic solvents were removed under reduced pressure and the residue was azeotropically evaporated with toluene several times. The residue was then dissolved in anhydrous DCM (18 mL) and DIPEA (0.99 g, 7.6 mmol) and di-tert-butyl dicarbonate (0.84 g, 3.8 mmol) were added. The solution was stirred at ambient temperature for 4 h. The crude reaction mixture was concentrated under reduced pressure and the residue was purified by flash column chromatography (40 g silica gel, eluting with 0-100% EtOAc/DCM) to afford the desired product (0.33 g, 43%) and tert-butyl [(1R,2R,3S)-4-azido-2-{[tert-butyl(dimethyl)silyl]oxy}-3-cyclopropyl-1-(hydroxymethyl)butyl]carbamate (0.50 g, 50%). LCMS (ESI) calc. for C13H25N4O4 [M+H]+ m/z=301.2. found: 301.2. For tert-butyl [(1R,2R,3S)-4-azido-2-{[tert-butyl(dimethyl)silyl]oxy}-3-cyclopropyl-1-(hydroxymethyl)butyl]carbamate: LCMS (ESI) calc. for C19H38N4O4SiNa [M+Na]+ m/z=437.3. found 437.0

1. customThe volatile organic solvents were removed under reduced pressure
2. customthe residue was azeotropically evaporated with toluene several times
3. dissolutionThe residue was then dissolved in anhydrous DCM (18 mL)
4. stirringThe solution was stirred at ambient temperature for 4 h
5. customThe crude reaction mixture
6. concentrationwas concentrated under reduced pressure
7. customthe residue was purified by flash column chromatography (40 g silica gel, eluting with 0-100% EtOAc/DCM)