反应详情

To a solution of 169 mg (0.68 mmol) of ethyl 2-{[(2R)-1,4-dioxan-2-ylmethyl]sulfanyl}-2-methylpropanoate in THF/water (1/1, 10 mL) are added 102 mg (1.36 mmol) of lithium hydroxide monohydrate. The reaction is stirred at room temperature for 18 d h. Then additional THF/water (1/1, 10 mL) is added and the reaction is for further 48 h. The reaction mixture is concentrated under reduced pressure. The aqueous residue is washed with diether ether (10 mL), then acidified with 6M aqueous HCl solution and extracted with ethyl acetate (3×10 mL). The combined organic extracts are dried (MgSO4), filtered and the filtrate is concentrated under reduced pressure to afford 147 mg of 2-{[(2R)-1,4-dioxan-2-ylmethyl]sulfanyl}-2-methylpropanoic acid. Yield: 86%; ES-MS: m/z 243 [M+Na]; 1H NMR (500 MHz, CHLOROFORM-d) δ ppm 1.55 (6H, s), 2.65-2.72 (1H, m), 2.73-2.81 (1H, m), 3.32-3.41 (1H, m), 3.57-3.64 (1H, m), 3.68-3.77 (3H, m), 3.77-3.86 (2H, m)

1. waitthe reaction is for further 48 h
2. concentrationThe reaction mixture is concentrated under reduced pressure
3. washThe aqueous residue is washed with diether ether (10 mL)
4. extractionextracted with ethyl acetate (3×10 mL)
5. dry with materialThe combined organic extracts are dried (MgSO4)
6. filtrationfiltered
7. concentrationthe filtrate is concentrated under reduced pressure