反应详情

To 166 g (0.63 mol) of 2-methyl-2-(tetrahydro-pyran-4-sulfonyl)-propionic acid ethyl ester in THF/water (4/1, 1.66 L) are added 50.5 g (1.26 mol) of NaOH pellets in portions over 20 min. The reaction is stirred at RT for 2.5 d. The organic solvent is removed under reduced pressure and the aq. residue is diluted with water (2 L) and washed with DCM (2 L). The aq. layer is acidified to pH 1-2 with concentrated HCl and then extracted with DCM (3×2 L). The acidic aqueous layer is further saturated with NaCl and extracted again with DCM (6×2 L). The combined organic extracts are concentrated under reduced pressure to give 123 g of 2-methyl-2-(tetrahydro-pyran-4-sulfonyl)-propionic acid. Yield: 83%; ESI-MS: 235 [M+H]+

1. customThe organic solvent is removed under reduced pressure
2. additionthe aq. residue is diluted with water (2 L)
3. washwashed with DCM (2 L)
4. extractionextracted with DCM (3×2 L)
5. extractionextracted again with DCM (6×2 L)
6. concentrationThe combined organic extracts are concentrated under reduced pressure