反应详情

To a solution of 2-acetyl-2,3-dihydro-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.5 g, 1.95 mmol) in chloroform (50 mL) is added 10 g of manganese dioxide (manufactured by Aldrich Corp., 90% manganese dioxide, for battery cell, <10 micron), and the resulting suspension is heated to reflux for 3 days. The mixture is cooled to room temperature, and then filtered. The filtrate is evaporated in vacuo and the residue is purified by silica gel column chromatography (eluent: chloroform) to give 2-acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.216 g, 44%) and 2-acetyl-2,3-dihydro-5-hydroxynaphtho[2,3-b]furan-4,9-dione (0.255 g, 51%). This method provides a method for preparing 2-acetyl-5-hydroxynaphtho[2,3-b]furan-4,9-dione at lower cost than Example 6.

1. temperaturethe resulting suspension is heated
2. temperatureto reflux for 3 days
3. filtrationfiltered
4. customThe filtrate is evaporated in vacuo
5. customthe residue is purified by silica gel column chromatography (eluent: chloroform)