反应详情

温度

70 °C

To a solution of 2-methoxymethyl-3-benzyloxy-pyran-4(1H)-one (2.46 g, 10 mmol, 1 eq.) in ethanol (10 ml)/water (10 ml) was added 1.93 g (30 mmol, 3 eq.) of 70% aqueous ethylamine followed by 2N sodium hydroxide solution until pH 13 was obtained. The reaction mixture was sealed in a thick-walled glass tube and stirred at 70° C. overnight. After adjustment to pH 1 with concentrated hydrochloric acid, the solvent was removed by rotary evaporation prior to addition of water (50 ml) and washing with diethyl ether (3×50 ml). Subsequent adjustment of the aqueous fraction to pH 7 with 10N sodium hydroxide solution was followed by extraction into dichloromethane (4×50 ml), the combined organic layers then being dried over anhydrous sodium sulphate, filtered and the solvent removed in vacuo. The residue was purified by column chromatography on silica gel (eluant: 15% CH3OH/85% CHCl3) to afford the title compound (2.05 g, 75.1%) as a yellow oil.

1. customwas obtained
2. customThe reaction mixture was sealed in a thick-walled glass tube
3. customAfter adjustment to pH 1 with concentrated hydrochloric acid, the solvent was removed by rotary evaporation
4. additionto addition of water (50 ml)
5. washwashing with diethyl ether (3×50 ml)
6. extractionSubsequent adjustment of the aqueous fraction to pH 7 with 10N sodium hydroxide solution was followed by extraction into dichloromethane (4×50 ml)
7. dry with materialthe combined organic layers then being dried over anhydrous sodium sulphate
8. filtrationfiltered
9. customthe solvent removed in vacuo
10. customThe residue was purified by column chromatography on silica gel (eluant: 15% CH3OH/85% CHCl3)