反应详情

A solution of 2-(4-allyldimethylsilylphenyl)-1,3-dioxolane (3 Scheme 18, 12 g, 52.5 mmol) and p-toluenesulfonic acid (100 mg) in acetone (300 mL) was heated under reflux for 3 h. The reaction mixture was concentrated under reduced pressure, and acetone (300 mL) was added to the residue. After refluxing for 3 h, the solution was concentrated, and the crude oil was purified by silica gel chromatography (1:20 ethyl acetate/hexanes) to afford a colorless oil (9.2 g, 86%); 1H NMR (300 MHz, CDCl3) δ 0.32 (s, 6 H), 1.78 (d, J=8.10 Hz, 2 H), 4.84 (s, 1 H) 4.89 (m, 1 H), 5.76 (m, 1 H), 7.67 (d, J=8.10 Hz, 2 H), 7.85 (d, J=8.10 Hz, 2 H), 10.05 (s, 1 H); 13C NMR (75 MHz, CDCl3) −3.4 (2C), 23.5, 114.2, 128.8 (2C) 133.7, 134.4, (2C), 136.9, 147.6, 192.8; HRMS calcd for C12H16OSi 204.0971, found 204.0972.

1. temperatureunder reflux for 3 h
2. concentrationThe reaction mixture was concentrated under reduced pressure, and acetone (300 mL)
3. additionwas added to the residue
4. temperatureAfter refluxing for 3 h
5. concentrationthe solution was concentrated
6. customthe crude oil was purified by silica gel chromatography (1:20 ethyl acetate/hexanes)