反应详情

To a solution of 20 (1.11 g, 2.94 mmol) in THF (anhydrous, 10 mL) and cooled in an ice bath was added dropwise MeMgCl (3 M solution in diethyl ether, 3.92 mL, 11.75 mmol) over 10 min, and stirring continued at 0° C. for 6 h. The reaction was quenched by the slow addition of methanol (10 mL), and then concentrated under vacuum. The residue was chromatographed (silica gel, a gradient of 0:100 to 18:82 ethyl acetate/hexanes) to afford the desired product 21 (0.78 g, 80% yield) as a white solid: 1H NMR (300 MHz, CDCl3) δ 1.26 (m, 12H), 1.49-1.57 (m, 4H), 2.13 (s, 3H), 2.41 (m, 2H), 3.19 (m, 5H), 5.09 (s, 2H), 7.34 (m, 5H); m/z (ESI) 334 [M+H]+.

1. customThe reaction was quenched by the slow addition of methanol (10 mL)
2. concentrationconcentrated under vacuum
3. customThe residue was chromatographed (silica gel