反应详情

3.2 G. of (3,4,5-trimethyl-2-thenyl)triphenyl phosphonium bromide were suspended in 80 ml. of butylene oxide and 1.5 g. of 3-methyl-7-formyl-octa-2,4,6-trienoic acid ethyl ester were added. The resulting mixture was refluxed under argon for one hour after which the solvent was evaporated. The residue which formed was diluted with a mixture of methanol/water (6:4) and extracted four times with hexane. The combined hexane solutions were washed once with methanol/water (6:4) and twice with pure water, dried with sodium sulfate, filtered and evaporated. The resulting crude product was purified by column chromatography on silica gel and elution with hexane/5% ether. Recrystallization of the all trans-3,7-dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester so obtained from hexane/1% ethyl acetate gave yellow crystals, m.p. 96°-98° C.

1. temperatureThe resulting mixture was refluxed under argon for one hour after which the solvent
2. customwas evaporated
3. customThe residue which formed
4. extractionextracted four times with hexane
5. washThe combined hexane solutions were washed once with methanol/water (6:4) and twice with pure water
6. dry with materialdried with sodium sulfate
7. filtrationfiltered
8. customevaporated
9. customThe resulting crude product was purified by column chromatography on silica gel and elution with hexane/5% ether
10. customRecrystallization of the all trans-3,7-dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester
11. customso obtained from hexane/1% ethyl acetate
12. customgave yellow crystals, m.p. 96°-98° C.