HCID 12651433, compound → HCID 12651440, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 6.06 ml. (14.4 mmol) of n-butyllithium (2.3 M in hexane) was added dropwise under argon, at -72° C., to a stirred suspension of 4.61 g. (10 mmol) of 4-methoxy-2,3,6-trimethylbenzyl triphenylphosphonium chloride in 25 ml. of dry tetrahydrofuran. After addition of reagent was complete the mixture was stirred at -30° C. until an orange solution was formed. The resulting solution was first cooled to -72° C. and then treated dropwise with a solution of 2.03 g. (9.0 mmol) of ethyl (E,Z,E)-4-fluoro-3,7-dimethyl-8-oxo-2,4,6-octatrienoate in 10 ml. of dry tetrahydrofuran. The reaction mixture was gradually allowed to come to 25° C. and further stirred at this temperature under argon for 2.0 hours. It was poured onto 100 ml. of cold water and extracted with methylene chloride (4×100 ml.). The combined organic extracts were washed with water (2×100 ml.) dried over anhydrous magnesium sulfate and concentrated to give 6.4 g. of oily crude product. This material was filtered through 300 g. of florisil and eluted with methylene chloride to yield 2.97 g. of yellow crystalline substance, which on crystallization from ether-petroleum ether (~1:9) afforded ethyl (E,Z,E,E)-9-(4-methoxy-2,3,6-trimethylphenyl)-4-fluoro-3,7-dimethyl-2,4,6,8-nonatetraenoate as yellow crystals, mp 92°-96° C.

Provenance & Evidence