反应详情

To a mixture of ethyl 5-(1-hydroxyethyl)-1,3-dioxane-5-carboxylate (16.8 g, 83 mmol) in dry pyridine (40 mL) at 0° C. was added 4-toluenesulfonyl chloride (19.1 g, 99 mmol). The mixture was stirred at rt for 16 h. Water (40 mL) was added, and the mixture was extracted with ethyl acetate (2×400 mL). The organic layer was washed with brine (3×). After concentrated in vacuo, the crude product was purified by silica gel chromatography eluting with petroleum ether/ethyl acetate 25:1 to 5:1 to provide the title compound (22.7 g, 76%) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 1.26 (m, 3H), 1.34 (d, J=6.8 Hz, 3H), 2.45 (s, 3H), 3.80 (d, J=11.6 Hz, 1H), 3.87 (d, J=11.6 Hz, 1H), 4.02 (d, J=11.6 Hz, 1H), 4.08 (d, J=12.0 Hz, 1H), 4.20-4.17 (m, 2H), 5.03-4.98 (m, 1H), 7.34 (d, J=8.0 Hz, 2H), 7.79 (d, J=8.8 Hz, 2H).

1. extractionthe mixture was extracted with ethyl acetate (2×400 mL)
2. washThe organic layer was washed with brine (3×)
3. concentrationAfter concentrated in vacuo
4. customthe crude product was purified by silica gel chromatography
5. washeluting with petroleum ether/ethyl acetate 25:1 to 5:1