反应详情

A 4 neck 1 liter round bottomed flask was charged with 400 g of dry isopropanol and 100 g of aluminum isopropoxide (0.48 mole). The contents of the flask were refluxed (80° C.) and 200 g of 2,4-dimethyl-2-(2,2,3-trimethylcyclopent-3-en-1-yl)-4-pentenal at 95.2% (0.865 mole) were added dropwise under nitrogen over 80 minutes. The reaction was refluxed for 2 hours. Then the lights were distilled off to a pot temperature of 110° C. After cooling the batch was extracted with 150 ml of 10% sulfuric acid and 300 ml of hexane. The hexane extract was washed with 150 ml of water, 100 ml of 5% sodium carbonate, and 100 ml of brine. After drying with magnesium sulfate, the batch was filtered, concentrated in vacuo and the crude alcohol, 201.1 g, was distilled from 1 g of soda ash to afford 193.6 g of purified product (88% yield). BP 94° C./0.10 mmHg; 1H-NMR (300 MHz), δ 1.007 (3H, s), 1.02 (3H, s), 1.42 (3H, s), 1.54 (3H, s), 1.83 (4H, br s), 2.0-2.4 (5H, br m), 3.60 (2H, AB quartet, JAB =11.1 Hz), 4.75 (1H, s), 4.88 (1H, s), 5.27 (1H, s); 13C-NMR (75 MHz), δ 12.35, 20.07, 22.31, 25.48, 28.38, 30.96, 42.11, 45.10, 48.27, 54.77, 68.48, 114.81, 121.38, 144.22, 148.28; IR (Neat), 3400 br, 2980, 1040 cm-1 ; MS (m/e), 207 (M+ -15), 191, 109 (Base).

1. additionwere added dropwise under nitrogen over 80 minutes
2. temperatureThe reaction was refluxed for 2 hours
3. distillationThen the lights were distilled off to a pot temperature of 110° C
4. temperatureAfter cooling the batch
5. extractionwas extracted with 150 ml of 10% sulfuric acid and 300 ml of hexane
6. extractionThe hexane extract
7. washwas washed with 150 ml of water, 100 ml of 5% sodium carbonate, and 100 ml of brine
8. dry with materialAfter drying with magnesium sulfate
9. filtrationthe batch was filtered
10. concentrationconcentrated in vacuo
11. distillationthe crude alcohol, 201.1 g, was distilled from 1 g of soda ash