反应详情

The product of Step 1 (1.698 g, 6.33 mmol) was dissolved in methanol (6 ml). Potassium fluoride (0.404 g, 6.96 mmol) was added, and the solution was maintained at room temperature for 1 hour. The solution was concentrated in vacuo. Purification via silica gel column chromatography (0-25% EtOAc:Hexanes) afforded ethyl 7-oxospiro[2.5]octane-4-carboxylate (251 mg, 20%) as a colorless oil. 1H NMR (500 MHz, CDCl3) δ 4.27-4.14 (m, 2H), 2.90 (d, J=14.9, 1H), 2.66 (ddd, J=5.6, 11.4, 16.8, 1H), 2.42-2.25 (m, 2H), 2.15-2.04 (m, 2H), 1.68 (d, J=14.9, 1H), 1.34-1.26 (m, 3H), 0.76-0.67 (m, 1H), 0.50-0.40 (m, 2H), 0.40-0.31 (m, 1H).

1. concentrationThe solution was concentrated in vacuo
2. customPurification via silica gel column chromatography (0-25% EtOAc:Hexanes)