反应详情

To a stirred solution of triethyl 2-phosphonopropionate (4.2 g) in THF (25 ml) under nitrogen is added sodium hydride (0.69 g of 60% dispersion in oil). After 30 minutes, 5-(2,6,6-trimethyl-1-cyclohexen-1-yl)pentanal (3.09 g) is added, and the mixture is stirred at reflux for16 hr. The reaction is cooled, poured into aqueous sodium bicarbonate, and extracted with ether. The extracts are concentrated and chromatographed with 30% dichloromethane in hexane to provide (2E)-2-methyl-7-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-heptenoic add ethyl ester as a colorless oil (2.4 g). This material (2.09 g) is reacted with diisobutylaluminum hydride (10 ml of 1.5M toluene solution) in toluene (20 ml) at -20° , stirred at 0° for 3 hr, then stirred for 16 hr with 1.0N sodium hydroxide solution. The mixture is extracted with ether, and the organic phase is concentrated and chromatographed with dichloromethane to provide 1.6 g of (2E)-2-methyl-7-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-heptenol as a colorless oil.

1. temperatureat reflux for16 hr
2. temperatureThe reaction is cooled
3. extractionextracted with ether
4. concentrationThe extracts are concentrated
5. customchromatographed with 30% dichloromethane in hexane
6. customto provide (2E)-2-methyl-7-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-heptenoic
7. stirringstirred at 0° for 3 hr
8. extractionThe mixture is extracted with ether
9. concentrationthe organic phase is concentrated
10. customchromatographed with dichloromethane