反应详情

A solution of 10.29 g of diethyl 2-[5-(2-methoxyethoxy)methoxypentyl]malonate (prepared as described in Preparation 41) dissolved in 100 ml of tetrahydrofuran was added dropwise to 2.40 g of lithium aluminum hydride dispersed in 100 ml of tetrahydrofuran, whilst ice-cooling (at 5° to 7° C.). The mixture was stirred at room temperature for 3 hours, and then 9.60 ml of a 4% w/v aqueous solution of sodium hydroxide was added dropwise at 5° to 9° C. After stirring the mixture for 30 minutes at room temperature, it was filtered with a Celite filter aid, and the filtrate was concentrated by evaporation under reduced pressure. The residue was subjected to column chromatography through 105 g of silica gel and 6.94 g of the title compound were obtained from the fractions eluted with mixtures of methylene chloride and methanol ranging from 98:2 to 95:5 by volume, as a colorless oil.

1. temperaturecooling (at 5° to 7° C.)
2. stirringAfter stirring the mixture for 30 minutes at room temperature
3. filtrationit was filtered with a Celite
4. filtrationfilter aid
5. concentrationthe filtrate was concentrated by evaporation under reduced pressure