反应详情

1.5 ml of an aqueous solution containing 0.203 g of potassium hydroxide was added, whilst ice-cooling, to a solution of 1.029 g of diethyl 2-[5-(2-methoxyethoxy)methoxypentyl]malonate (prepared as described in Preparation 61) dissolved in 1.5 ml of ethanol. The reaction mixture was stirred at room temperature for 5 hours, after which it was washed with diethyl ether. The aqueous layer was adjusted to a pH value of 2 by adding 10% w/v aqueous hydrochloric acid, and it was then extracted four times with methylene chloride. The combined extracts were dried over anhydrous magnesium sulfate and concentrated by evaporation under reduced pressure. The oily residue (0.94 g) was subjected to column chromatography through 20 g of silica gel, and 0.764 g of the title compound was obtained, as a colorless oil, from those fractions eluted with mixtures of hexane and ethyl acetate ranging from 2:1 to 1:1 by volume.

1. additionwas added, whilst ice-
2. washafter which it was washed with diethyl ether
3. additionby adding 10%
4. extractionwas then extracted four times with methylene chloride
5. dry with materialThe combined extracts were dried over anhydrous magnesium sulfate
6. concentrationconcentrated by evaporation under reduced pressure