反应详情

To a solution of DCC (18.6 mg, 0.090 mmol) and formic acid (8.28 mg, 0.180 mmol) in CH2Cl2 that had been stirred at 0° C. for 10 min, was added intermediate 26a (30 mg, 0.045) in a solution of pyridine. The reaction was stirred at 0° C. for 15m then at rt for 2 h. The reaction mixture was concentrated in vacuo, then taken up in brine and extracted with chloroform (6×), dried (Na2SO4) and concentrated. It was purified by SiO2 chromatography (gradient elution, 1–12% MeOH/CH2Cl2) to afford 23.3 mg (75%) of intermediate 42a. MS (ESI) 692.2 (M+H+).

1. concentrationThe reaction mixture was concentrated in vacuo
2. extractionextracted with chloroform (6×)
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated
5. customIt was purified by SiO2 chromatography (gradient elution, 1–12% MeOH/CH2Cl2)