反应详情

温度

100 °C

Paraformaldehyde (843 mg, 9.26 mmol) and 10-camphorsulfonic acid (75 mg, 0.324 mmol) were added to a solution of (R)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butyldisulfanyl)propanoic acid (Compound 2α-B) (2.00 g, 4.63 mmol) in toluene (10 ml), and the mixture was stirred at 100° C. for 4 hours. The reaction mixture was returned to room temperature and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=100/0→70/30) to afford (R)-(9H-fluoren-9-yl)methyl 4-((tert-butyldisulfanyl)methyl)-5-oxooxazolidine-3-carboxylate (Compound 2b-B) (1.936 g, 94%).

1. customwas returned to room temperature
2. concentrationconcentrated under reduced pressure
3. customThe resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate=100/0→70/30)