反应详情

温度

40 °C

The corresponding Grignard-reagent is prepared form 2-(4-bromo-3,5-dimethyl-phenyl)-[1,3]dioxane (2.5 g, 9.22 mmol) and Mg (258 mg, 10.6 mmol) in THF (50 mL). To this reagent allylbromide (1.23 g, 10.14 mmol) is added dropwise at rt. The reaction mixture becomes warm (40° C.) and it is stirred for 16 h. The reaction is quenched by adding water. The mixture is extracted with EA. The organic extract is dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 10:1 to give 2-(4-allyl-3,5-dimethyl-phenyl)-[1,3]dioxane (1.8 g) as a colourless oil; LC-MS: tR=1.02 min, [M+1]+=233.22, 1H NMR (CDCl3): δ 7.12 (s, 2H), 5.94-5.80 (m, 1H), 5.44 s, 1H), 4.95 (dd, J=1.8, 10.0 Hz, 1H), 4.80 (dd, J=1.8, 17.0 Hz, 1H), 4.30-4.21 (m, 2H), 4.04-3.92 (m, 2H), 3.40-3.34 (m, 2H), 2.32-2.26 (m, 8H).

1. customThe reaction is quenched
2. additionby adding water
3. extractionThe mixture is extracted with EA
4. extractionThe organic extract
5. dry with materialis dried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product is purified by CC on silica gel eluting with heptane:EA 10:1