反应详情

A solution of diisopropylazodicarboxylate (2.12 g, 10.5 mmol) in THF (25 mL) was added via syringe pump over 1.5 h to a mixture of 4-propylphenol (purchased from Aldrich Chemical Co.) (1.36 g, 10.0 mmol), 6-bromo-1-hexanol (purchased from Aldrich Chemical Co.) (1.81 g, 10.0 mmol), and triphenylphosphine (2.75 g, 10.5 mmol) in THF (25 mL) at 0° C. under argon. The slightly yellow reaction was stirred at 0° C. for 30 min, whereupon additional triphenylphosphine (262 mg, 1.00 mmol) was added, followed by addition of diisopropylazodicarboxylate (200 mL, 1.0 mmol) over 30 min. The reaction was allowed to warm to RT, at which time silica gel (15 g) was added. The mixture was concentrated in vacuo and the white powder obtained was purified by flash chromatography on silica gel (150 g) eluted with a step gradient of hexane to 2:98 EtOAc/hexane. The slightly impure product obtained was rechromatographed on silica gel (150 g) eluted with 1:99 EtOAc/hexane to give title compound (2.00 g, 67%) as a colorless oil.

1. customThe slightly yellow reaction
2. additionwas added
3. additionwas added
4. concentrationThe mixture was concentrated in vacuo
5. customthe white powder obtained
6. customwas purified by flash chromatography on silica gel (150 g)
7. washeluted with a step gradient of hexane to 2:98 EtOAc/hexane
8. customThe slightly impure product obtained
9. customwas rechromatographed on silica gel (150 g)
10. washeluted with 1:99 EtOAc/hexane