反应详情

20 ml of a 1M solution of potassium tert-butylate in tetrahydrofuran are added dropwise at 0° C. under an inert atmosphere to a suspension of 0.02 mol of (ethoxycarbonylmethyl)triphenylphosphonium bromide in 90 ml of tetrahydrofuran. After the addition is complete and the mixture has returned to room temperature, 0.01 mol of the compound obtained in Step E of Example 1 diluted in 30 ml of tetrahydrofuran is added. After 12 hours, the reaction mixture is hydrolysed by the addition of 100 ml of a 1N HCl solution, and then extracted with ethyl acetate; the combined organic phases are washed with water and then with a saturated NaCl solution, dried over sodium sulphate, filtered and concentrated under reduced pressure. Chromatography over silica gel (pentane/ethyl acetate: 90/10) enables 2.78 g of the expected product to be isolated.

1. additionAfter the addition
2. customhas returned to room temperature
3. additionis added
4. extractionextracted with ethyl acetate
5. washthe combined organic phases are washed with water
6. dry with materialwith a saturated NaCl solution, dried over sodium sulphate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customto be isolated