反应详情

To a solution of 1,5-dioxa-9-aza spiro[5.5]undecane (15.0 g, 95.4 mmol) and triethylamine (17.6 mL, 126 mmol) in THF (140 mL) cooled to 0° C. was added dropwise a solution of benzyl chloroformate (14 mL, 97.5 mmol) dissolved in THF (30 mL). The resulting mixture was stirred at room temp for 18 h. After diluting with EtOAc, the mixture was washed with water and brine and dried (Na2SO4). Concentration gave yellow oil that was purified by flash chromatography eluting with 20%-50% EtOAc/hexane to give the title compound as colorless oil (18.9 g, 68% yield). 1H NMR (300 MHz, CDCl3) δ: 7.36-7.27 (5H, m), 5.09 (2H, s), 3.89-3.85 (4H, m), 3.51-3.47 (4H, m), 1.87-1.66 (6H, m). LCMS (M+H) calcd for C16H22NO4: 292.15; found: 292.00.

1. washthe mixture was washed with water and brine
2. dry with materialdried (Na2SO4)
3. concentrationConcentration
4. customgave yellow oil that
5. customwas purified by flash chromatography
6. washeluting with 20%-50% EtOAc/hexane