反应详情

A solution of 2(R)-[4-methoxy-3-(3-methoxypropoxy)-benzyl]-3-methyl-butyric acid (186 g) in tetrahydrofuran (500 ml) is added slowly at room temperature to a suspension of sodium borohydride (27.2 g) in tetrahydrofuran (1.5 liters). The mixture is stirred until the evolution of gas has ceased (about 45 minutes), and then a solution of iodine (76.2 g) in tetrahydrofuran (1.0 liter) is slowly added and the reaction mixture is stirred at room temperature for a further 4 days. Methanol (1.0 liter) is carefully added dropwise over a period of 20 minutes and after a further 30 minutes' stirring the mixture is concentrated in vacuo. The residue is extracted with ethyl acetate (3×2 liters) and the combined organic phases are washed in succession with 2 liters each of 2N hydrochloric acid, water, saturated sodium thiosulfate solution, water, 0.1N sodium hydroxide solution (1 liter) and saturated sodium chloride solution, dried over magnesium sulfate and concentrated. The residue is purified by FC on silica gel (ethyl acetate/hexane 1:1) and the title compound is obtained in the form of an oil (160 g): Rf (ethyl acetate/hexane 1:1)=0.28. Anal. C17H28O4 (296.41): C, 68.89; H, 9.52; found C, 68.34; H, 9.70.

1. custom(about 45 minutes)
2. stirringthe reaction mixture is stirred at room temperature for a further 4 days
3. stirringstirring the mixture
4. concentrationis concentrated in vacuo
5. extractionThe residue is extracted with ethyl acetate (3×2 liters)
6. washthe combined organic phases are washed in succession with 2 liters each of 2N hydrochloric acid, water, saturated sodium thiosulfate solution, water, 0.1N sodium hydroxide solution (1 liter) and saturated sodium chloride solution
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated
9. customThe residue is purified by FC on silica gel (ethyl acetate/hexane 1:1)