反应详情

Ethyl 2-cyano-2-methyl-3-methylsulfanyl-propanoate (2.3 g, 12.3 mmol) was added to ice-cold sodium hydroxide (5 mL, 2N) under stirring. Methanol (10 mL) was added and the ice bath removed after an hour. After 45 minutes at room temperature, volatiles were removed under reduced pressure and the residue diluted with water (20 mL). Impurities were removed by ether extraction (2×30 mL). The aqueous layer was cooled in ice, acidified to pH 3 with dilute HCl and extracted with ethyl acetate (3×30 mL). Combined organic extracts were dried over MgSO4 and concentrated under reduced pressure to leave a brown gum. Yield 1.32 g (68%): IR (KBr thin film) 1735 cm−1; 1H NMR (400 MHz, CDCl3) δ 10.19 (br, 1H), 3.10 (d, J=14.2 Hz, 1H), 2.94 (d, J=13.9 Hz, 1H), 2.33 (s, 3H), 1.73 (s, 3H); 13C NMR (400 MHz, CDCl3) δ 173.33, 118.82, 45.86, 41.66, 23.05, 17.62.

1. customthe ice bath removed after an hour
2. customvolatiles were removed under reduced pressure
3. additionthe residue diluted with water (20 mL)
4. customImpurities were removed by ether extraction (2×30 mL)
5. temperatureThe aqueous layer was cooled in ice
6. extractionextracted with ethyl acetate (3×30 mL)
7. dry with materialCombined organic extracts were dried over MgSO4
8. concentrationconcentrated under reduced pressure
9. customto leave a brown gum