反应详情

温度

-25 °C

A solution of 3.0 g (15.6 mmol) of 2-ethoxycarbonyl-1,3-dithiane in 40 ml of dry tetrahydrofuran was cooled under inert atmosphere to -78° C. and treated with 7.5 ml (15.6 mmol) of n-butyllithium. The resulting solution was warmed to -25° C., stirred for 20 min, recooled to -78° C., treated with 1.8 ml (15.6 mmol) of benzyl chloride, and stirred at ambient temperature for 16 h. After quenching with aqueous ammonium chloride, the mixture was extracted with ether, washed sequentially with water, aqueous sodium thiosulfate, and brine, dried over MgSO4, and concentrated in vacuo. Flash chromatography using 5% ethyl acetate in hexane gave 3.9 g (88%) of the desired compound. 1H NMR (CDCl3) δ 1.33 (t, J=7 Hz, 3H), 1.85 (qt, J=14, 3 Hz, 1H), 2.11 (dm, J=14 Hz, 1H), 2.69 (dt, J=14, 4 Hz, 2H), 3.23 (ddd, J=14, 12, 3 Hz, 2H), 3.38 (s, 2H), 4.27 (q, J=7 Hz, 2H), 7.25-7.35 (m, 5H). Mass spectrum (M+NH4)+ =300.

1. customrecooled to -78° C.
2. stirringstirred at ambient temperature for 16 h
3. customAfter quenching with aqueous ammonium chloride
4. extractionthe mixture was extracted with ether
5. washwashed sequentially with water, aqueous sodium thiosulfate, and brine
6. dry with materialdried over MgSO4
7. concentrationconcentrated in vacuo