Tetrahydrofuran → trans-3,7-Dimethyl-9-(3,4,5-trimethyl-2-thienyl)-2,4,6,8-nonatetraenoic acid ethyl ester

Participants

Reaction Steps

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.

Provenance & Evidence