反应详情

3-methoxycatechol (25 g) was dissolved in benzene, mixed with dimethoxyacetal (35 ml) and a catalytic amount of tosylic acid, and then, heat-refluxed for 6 hours. The resultant was allowed to stand for cooling, alkalified by adding an aqueous sodium hydroxide solution, and extracted with ether. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over manganese sulfate, and evaporated under reduced pressure for removing the solvent. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1) to give Compound IIbv-a (19.4 g, 60.5%) as a white solid.

1. temperaturefor cooling
2. extractionextracted with ether
3. washThe organic layer was washed with a saturated aqueous sodium chloride solution
4. dry with materialdried over manganese sulfate
5. customevaporated under reduced pressure
6. customfor removing the solvent
7. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=99/1)
8. customto give Compound IIbv-a (19.4 g, 60.5%) as a white solid