p-Toluenesulfonic acid → 2,2,4-Trimethyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)tetrahydrofuran
反応式
[CH3:1][C:2]1([CH3:16])[C:6]([CH3:7])=[CH:5][CH2:4][CH:3]1[C:8]([CH3:15])([CH2:11][C:12]([CH3:14])=[CH2:13])[CH2:9][OH:10].CC1C=CC(S(O)(=O)=O)=CC=1>CCCCCCC>[CH3:13][C:12]1([CH3:14])[CH2:11][C:8]([CH3:15])([CH:3]2[CH2:4][CH:5]=[C:6]([CH3:7])[C:2]2([CH3:16])[CH3:1])[CH2:9][O:10]1参加物
4
実験手順
A 1 liter 3 neck round bottomed flask was charged with 600 ml of heptane, 155.3 g of 2-(2,2,3-trimethylcyclopent-3-en-1-yl)-2,4-dimethyl-4-pentenol at 97.7% (0.68 mole) and 0.9 g of p-TSA. The batch was refluxed under nitrogen for 26 hours. Then batch was cooled and washed with 500 ml of 10% sodium carbonate, 500 ml of water and 500 ml of brine. The batch was dried with magnesium sulfate, filtered, and concentrated in vacuo to afford 163.3 g of crude product. Distillation of the product afforded 150.3 g of purified product (92.7%). BP 84° C./0.5 mmHg; 1H-NMR (300 MHz), δ0.92 (3H, s), 1.10 (3H, s), 1.20 (3H, s), 1.25 (3H, s), 1.33 (3H, s), 1.55 (4H, sharp m), 1.81-1.99 (2H, m), 2.16 (2H, br m), 3.60 (2H, AB quintet J=8.7 Hz), 5.24 (1H, s); 13C-NMR (75 MHz), δ12.35, 22.03, 24.57, 25.66, 28.69, 29.96, 32.48, 47.38, 48.36, 50.58, 57.22, 77.63, 80.60, 121.20, 148.01; IR (Neat), 3020, 2980, 1450, 1060 cm-1 ; MS (m/e), 222 (M+), 207, 191, 95, 43;