反应详情

A suspension of 24.3 g (0.22 mole) of potassium tert-butoxide in 240 ml of dimethyl sulfoxide under a nitrogen atmosphere was stirred and cooled in a cold water bath while a solution of 29.2 g (0.18 mole) of 3,4-dihydro-7-hydroxy-1(2H)-naphthalenone in 400 ml of dimethyl sulfoxide was added dropwise over 45 minutes. The mixture was stirred at room temperature for an additional 45 minutes, and then 23.7 ml (31.0 g; 0.25 mole) of 2-bromopropane was added in one portion. After stirring for an additional 30 hours, the mixture was added to 2.0 kg of ice/water and extracted with dichloromethane (4×300 ml). The combined organic layers were back-washed with water (2×150 ml), dried (anhydrous magnesium sulfate), and evaporated (vacuum) to an oil residue. Flash chromatographic purification (silica gel, dichloromethane elution) of the residue yielded 24.0 g (65% yield) of the analytically pure ether product as an oil, suitable for conversion to the naphthol described in Example 4.

1. additionwas added dropwise over 45 minutes
2. stirringThe mixture was stirred at room temperature for an additional 45 minutes
3. stirringAfter stirring for an additional 30 hours
4. extractionextracted with dichloromethane (4×300 ml)
5. washThe combined organic layers were back-washed with water (2×150 ml)
6. dry with materialdried (anhydrous magnesium sulfate)
7. customevaporated (vacuum) to an oil residue
8. customFlash chromatographic purification (silica gel, dichloromethane elution) of the residue
9. customyielded 24.0 g (65% yield) of the analytically pure ether product as an oil