反应详情

温度

0 °C

At 0° C., to a solution of ethyl 4-methylenecyclohexanecarboxylate (0.08 g) in DCE (1 mL) was added chloroiodomethane (0.110 mL, 1.522 mmol), followed by the addition of 1 N diethylzinc in hexane (0.761 mL, 0.761 mmol). The reaction was stirred at 0° C. for 1 hr, then stirred at rt for 18 hrs. The reaction mixture was diluted with EtOAc and 1 N HCl, the organic phase was washed with sat. NaCl, dried over anhydrous Na2SO4, filtered and concentrated. The crude product was charged to a 25 g silica gel cartridge which was eluted with a 20 min gradient of 0-6% EtOAc in hexane to yield ethyl spiro[2.5]octane-6-carboxylate. 1H NMR (400 MHz, CDCl3) δ ppm 4.08-4.18 (2H, m), 2.32 (1H, tq, J=11.01, 3.53 Hz), 1.85-1.93 (2H, m), 1.53-1.74 (4H, m), 1.28-1.35 (2H, m), 1.22-1.28 (3H, m), 0.28 (2H, ddd, J=8.53, 5.52, 1.51 Hz), 0.17-0.25 (2H, m).

1. stirringstirred at rt for 18 hrs
2. washthe organic phase was washed with sat. NaCl
3. dry with materialdried over anhydrous Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. additionThe crude product was charged to a 25 g silica gel cartridge which
7. washwas eluted with a 20 min gradient of 0-6% EtOAc in hexane