反应详情

4.50 g of [1-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)ethyl]triphenylphosphonium bromide and 1.3 g of ethyl 5-formyl-3-methylpenta-2,4-dienoate are dissolved in 70 ml of butylene oxide and the solution is heated at reflux for 2 hours. The cooled mixture is poured into a methanol/water mixture (6:4) and extracted several times with hexane. The hexane phase is washed three times with water, dried and evaporated. After filtration of the crude product over silica gel (eluting agent hexane/ether 9:1), there are obtained 2.4 g of ethyl 3-methyl-7-(4,5,6,7-tetrahydro-4,4,7,7-tetramethylbenzo[b]thien-2-yl)-2,4,6-octatrienoate as a pale yellowish oil.

1. temperaturethe solution is heated
2. temperatureat reflux for 2 hours
3. extractionextracted several times with hexane
4. washThe hexane phase is washed three times with water
5. customdried
6. customevaporated
7. filtrationAfter filtration of the crude product over silica gel (eluting agent hexane/ether 9:1), there