反应详情

To a solution of 123 g (0.44 mol) of 2-methyl-2-(tetrahydro-pyran-4-ylmethanesulfonyl)-propionic acid ethyl ester in THF (450 mL) are added 663 mL of 2M aqueous sodium hydroxide solution (1.33 mol). The reaction is stirred at room temperature for 1 h. To the reaction mixture is added TBME (1.25 L) and the layers are separated. The aqueous layer is cooled in an ice bath and then acidified with 37% aqueous HCl solution (123 mL). The resulting precipitate is isolated by filtration, washed with water (200 mL) and dried under reduced pressure at 50° C. to afford 101 g of 2-methyl-2-(tetrahydro-pyran-4-ylmethanesulfonyl)-propionic acid as white crystalline solids. Yield: 91%; ES-MS: m/z 251 [M+H]; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.31-1.45 (2H, m), 1.49 (6H, s), 1.70-1.79 (2H, m), 2.13-2.28 (1H, m), 3.24 (2H, d, J=6.60 Hz), 3.28-3.38 (2H, m), 3.76-3.85 (2H, m), 13.65 (1H, br. s.)

1. customthe layers are separated
2. temperatureThe aqueous layer is cooled in an ice bath
3. customThe resulting precipitate is isolated by filtration
4. washwashed with water (200 mL)
5. customdried under reduced pressure at 50° C.