反应详情

A 100 mL round bottom flask was charged with t-butyl cyclooct-4-ene carboxylate (1.0 g, 4.8 mmol) and trifluoroacetic acid (2 mL) and stirred at room temperature for two days. A 4:1 ethanol:water mixture (10 mL) was then added and the pH of the resulting mixture was adjusted to ˜4.0 with aqueous saturated NaHCO3. The mixture was then extracted with 4×25 mL portions of ethyl ether and the ether phases were combined and concentrated. The liquid was then purified by flash chromatography on silica (3:7 ethyl acetate:hexanes mobile phase) to afford cyclooct-4-ene carboxylic acid (0.051 g, 69%). The material was crudely dried immediately before polymerization by dissolving the material in benzene and carrying out azeotropic distillation using a rotary evaporator (three cycles). IR (film on NaCl): 3017, 2932, 2859, 1736 (C═O), 1467, 1449, 1392, 1334, 1165, 747, 714 cm−1 (O—H stretch not assigned due to weakness). 1H NMR (300 MHz, CDCl3): δ 11.6 (br, 1H), 5.6–5.8 (m, 2H), 2.30–2.54, (m, 2H), 2.02–2.24 (m, 4H), 1.84–1.96 (m, 1H), 1.50–1.82 (m, 3H), 1.32–1.48 (m, 1H). 13C NMR (75 MHz, CDCl3): δ 184.34, 130.45, 129.34, 43.10, 31.28, 29.10, 27.65, 25.75, 23.92 ppm. HRMS-FAB for C8H14O2: Theoretical: 126.1045; Found: 126.1048.

1. extractionThe mixture was then extracted with 4×25 mL portions of ethyl ether
2. concentrationconcentrated
3. customThe liquid was then purified by flash chromatography on silica (3:7 ethyl acetate:hexanes mobile phase)