反应详情

温度

-70 °C

30 ml of n-BuLi 2.5 M in hexane (75 mmoles) are added to 20 g of 2-methoxy-2-(o-bromobenzyloxy)propane (77.22 mmoles) obtained as in example 1.1, in a solution of 150 ml of hexane. At the end of the addition the mixture is left under stirring for 2 hours. The precipitation of the corresponding lithium salt takes place, as previously described in example 1. The hexane is decanted and the solid is again washed with hexane and then dissolved in 100 ml of THF. The mixture is cooled to −70° C. and 12.12 g (75.75 mmoles) of 4,7-dimethyl-1-indanone obtained as described above, dissolved in-a sufficient quantity of THF, are then added slowly. The temperature is left to rise to room temperature for a night, the reaction mass is poured into ice, acidified with 50 ml of aqueous HCl 1/1 and left under stirring for 2 hours. It is extracted with ethyl ether, the organic phase is washed until neutrality with a solution of sodium bicarbonate and water, and is anhydrified on sodium sulfate. After evaporation of the solvent the residue is purified by chromatography on a silica gel column, eluating with a mixture of hexane/ethyl acetate 9:1. After evaporation of the eluant, 10 g of the alcohol having formula (XIX) are obtained (scheme V; 53% yield).

1. additionAt the end of the addition the mixture
2. waitis left
3. customThe precipitation of the corresponding lithium salt
4. customThe hexane is decanted
5. washthe solid is again washed with hexane
6. dissolutiondissolved in 100 ml of THF