反应详情

A solution of (S)-methyl 4-(1-hydroxyethyl)benzoate (24.8 g, 138 mmol) in toluene (300 mL) was cooled in ice-salt bath (bath temp: −10° C.). DPPA (36.3 mL, 168 mmol) was then added dropwise over 15 min (Bath temp was kept at −10° C. during addition). After 5 min, DBU (25.3 mL, 169 mmol) was added over 8 min. The ice in the bath was allowed to melt and the reaction mixture was stirred overnight at RT. The reaction mixture was diluted with EtOAc (200 mL), and washed with 0.1 N HCl aq. (300 mL). The aqueous layer was extracted with EtOAc (100 mL×2) and the combined organic phase was further washed with 0.1N HCl aq. (300 mL×2), 5% NaHCO3 (300 mL×2), and saturated NaCl (300 mL×2). The organic layers was dried over Na2SO4 and concentrated under reduced pressure. The crude product was chromatographed on SiO2 (ISCO: hexane/CH2Cl2=3/1→3/7) to yield the title compound. MS (m/z): 206.2 (m+H).

1. addition(Bath temp was kept at −10° C. during addition)
2. washwashed with 0.1 N HCl aq. (300 mL)
3. extractionThe aqueous layer was extracted with EtOAc (100 mL×2)
4. washthe combined organic phase was further washed with 0.1N HCl aq. (300 mL×2), 5% NaHCO3 (300 mL×2), and saturated NaCl (300 mL×2)
5. dry with materialThe organic layers was dried over Na2SO4
6. concentrationconcentrated under reduced pressure
7. customThe crude product was chromatographed on SiO2 (ISCO: hexane/CH2Cl2=3/1→3/7)