反应详情

温度

0 °C

Acetic anhydride (8 mL) was slowly added to a solution of (8) (1.25 g, 2.03 mmol) in pyridine (50 mL) and CH2Cl2 (30 mL) which had been cooled to 0° C. Stirring was continued at 0° C. for 30 minutes and then at room temperature overnight. Solvents were removed under high vacuum, and the residue was dissolved in CHCl3 (120 mL), followed by washing with 0.5N HCl (2×40 mL) and saturated NaHCO3 (2×40 mL). After solvent removal, the crude oil was purified by silica gel column chromatography, eluting with 3:1 EtOAc/hexane, to furnish 0.8 g (60%) of (9) as an oil: NMR δ 1.40-1.80 (m, 12 H), 2.05 (s, 3 H), 2.20-2.50 (m, 6 H), 3.40-3.73 (m, 6 H), 4.75 (s, 6 H) , 7.32 (s, 15 H). Anal. (C38H48N4O6) C, H, N.

1. customat room temperature
2. customovernight
3. customSolvents were removed under high vacuum
4. dissolutionthe residue was dissolved in CHCl3 (120 mL)
5. washby washing with 0.5N HCl (2×40 mL) and saturated NaHCO3 (2×40 mL)
6. customAfter solvent removal
7. customthe crude oil was purified by silica gel column chromatography
8. washeluting with 3:1 EtOAc/hexane