反应详情

To a solution of 1.029 g of diethyl 2-[5-(2-methoxyethoxy)methoxypentyl]malonate (prepared as described in Preparation 41) dissolved in ethanol (1.5 ml) was added an aqueous solution (1.5 ml) containing potassium hydroxide (0.203 g) whilst ice-cooling. 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% aqueous hydrochloric acid, and it was then extracted four times with methylene chloride. The combined extracts were dried and concentrated by evaporation under reduced pressure. The oily residue (0.94 g) was subjected to column chromatography through silica gel (20 g) and the title compound (0.764 g) Was obtained, as a colorless oil, from the fractions eluted with mixtures of hexane and ethyl acetate ranging from 2:1 to 1:1 by volume.

1. temperaturecooling
2. washafter which it was washed with diethyl ether
3. additionby adding 10% aqueous hydrochloric acid, and it
4. extractionwas then extracted four times with methylene chloride
5. customThe combined extracts were dried
6. concentrationconcentrated by evaporation under reduced pressure