反应详情

Add Tf2O (80 mL) dropwise to a cold (−78° C.) solution of 3-hydroxy-2-hydroxymethyl-2-methyl-propionic acid methyl ester (32.5 g) in CH2Cl2 (400 mL) and 2,6-lutidine (80 mL). The reaction is allowed to reach room temperature and stir until only product spot detected by TLC analysis (ca. 2 h). Dilute with CH2Cl2 (400 mL) and wash with HCl (3% aqueous solution). Dry the organic layer over MgSO4, filter and concentrate. Subject residue to silica gel chromatography eluting with hexanes/ethyl acetate 5%, to give 2-methyl-2,3-bis-trifluoromethanesulfonyloxy-propionic acid methyl ester as a colorless oil.

1. customto reach room temperature
2. customdetected by TLC analysis (ca. 2 h)
3. washwash with HCl (3% aqueous solution)
4. dry with materialDry the organic layer over MgSO4
5. filtrationfilter
6. concentrationconcentrate
7. washSubject residue to silica gel chromatography eluting with hexanes/ethyl acetate 5%