反应详情

To a stirred solution of 15.0 g (0.0867 mol) of the product from Example 12 in 240 mL dry tetrahydrofuran cooled to -78° was added dropwise 22.7 mL (0.0993 mol) of 25% sodium methoxide in methanol solution over 45 minutes. After warming to -20°, the mixture was poured into ice water, acidified with 1 normal hydrochloric acid and extracted with ether. The combined organic layers were washed with brine, dried over magnesium sulfate, and evaporated to a semisolid which was purified by flash chromatography to afford 3.2 g (17%) light yellow solid: m.p. 81°-82°; NMR (CDCl3, 200 MHz) 3.9 (3H, s), 3.98 (3H, s), 6.67 (1H, d, J=9 Hz), 8.25 (1H, m); IR (nujol) 1715, 1615, 1290 cm-1.

1. temperatureAfter warming to -20°
2. extractionextracted with ether
3. washThe combined organic layers were washed with brine
4. dry with materialdried over magnesium sulfate
5. customevaporated to a semisolid which
6. customwas purified by flash chromatography
7. customto afford 3.2 g (17%) light yellow solid